When you are re-reading my comments on electrical systems, keep in mind I am a firm believer in redundant life support systems and I am fond of overkill when it domes to system design :)
I prefer having too much to falling short. As I design my system for my personal Tacoma, I find myself struggling to figure out where to fit gauges and switches. I am seriously considering a raspberry pi system to trigger relays instead of using switches. (as stated above, I have plans for lots of lighting), even wiring a set of driving lights in the bumper to the low beam harness, and wiring the fog lights to the factory harness, I am still looking at around a dozen switches for lighting, 2 switches for a winch, 2-5 switches and a gauge for the OBA system I want to build (I had planned front and rear air lockers initially, but my truck has the rear e-locker, so my locker plans may change, but I will still need a switch added for the front locker if I get one according to my long term plans, and I still plan on putting an airbag in back instead of an add a leaf so it will require a switch, plus the compressor power switch (note, even I have mixed opinions about using airbag assisted suspension. They have several advantages including versitility, but they also have a number of disadvantages including being vulnerable to puncture on the trail), plus switched for remote power on my radio equipment and MAYBE a stereo amp. Designing a clean electrical system for the Tacoma is going to be a lot of work as I am now having to make drawings, blueprints, and schematics for things that had previously been ideas and plans or "well it worked on my ranger" :)
I would be interested in seeing what you have done to the truck already, or have planned to do to it as you turn it into your overlander. My truck is still less than a week old (for me), so I have not even gotten decent pictures of my starting point yet. Some of my plans started as plans for my ranger, but I got to a point where I no longer trusted it mechanically for out of state trips, much less things like my plans to head to New York for some camping and canoeing with an old friend once covid is actually under control.
My personal long term build plans (3-5 years) for a truck that is intended to be work truck, daily driver, overlander and trail rider both locally and hopefully on some long range expeditions (did I mention I am jealous of your Alaska plans?) :)
Lots of lighting as mentioned above. I have no expectation of needing all of it at once, but I want the versatility of having what I need when I need it. Including a bumper mount driving and fog lights as well as a bumper mount flood light, an optional set of ditch lights, a set of right and left ally lights mounted to the cargo rack, a set of forward rack mount driving and spot lights, a set of bumper mount flood lights (wired into the backup lights) and a set of rear facing flood lights angled down mostly for lighting up the tongue area of a trailer though a friend suggested mounting a LED light strip under the cargo rack instead as it should give me all the same lighting at a potentially lower cost and if made with RGB could also be wired so the red is wired into my brake lights (and while it was not part of my friends sugestion, I MIGHT be able to use the RGB to turn it amber as a "dust light" to add visibility on the trail) I will of course also be able to attach some trail tools (shovel, axe, pry bar, winch anchor, chain saw, etc) to the cargo rack as well as carrying spare fuel, water and a passenger side folding RTT on the cargo rack.
Lots of Communications gear I have CB and Ham radio equipment, I have plans of adding more ham radio gear, and eventually adding sat comm gear, plus if I start traveling more with groups, I would like to upgrade from a FRS/GMRS HT to a proper mobile radio
3"-4" lift front and rear (with proper rear replacement springs) I am looking at the ARB/OME 3x3 HD kit as it is not overly expensive, it is bolt in, and it is listed as being sufficient for the 33" tires I want without getting too high of a CoG. I intend to calculate the difference in tire size and see about getting regeared (I am presently thinking of nitro gears) to come as close to factory equivilent as possible.
A set of 5-8 matching off road tires (that will be pricey) so I have a matching set of 33" tires for my truck and the trailer I plan to build as well as a full size spare for each and a set of 4 matching AT tires for daily driving (my spare tire will be one of the off road tires)
A custom welded bed mounted cargo rack (I must confess I am having to completely redesign the mounting system as despite having been looking at 3rd gen Tacomas for the last couple years, I never thought to look and notice that they no longer have stake pockets and my mounting system has to be compatible with having a bed cap with side windoors (nearly full length swing up windows)
A custom bed drawer system (largely inspired by a bed drawer build by an DIY build I found on another site with a pair of 4' drawers, a pair of battery compartments for 2-4 "house batteries" forward of the wheel wells (the advantage of 6' bed), a pair of storage compartments behind the wheel wells to hold tools and roadside emergency kit, and a storage compartment forward of the drawers (I estimate 18" front to back, and a li'l less than the width of the space between the wheel wells, but I have not yet made final blueprints) I will be carpeting the whole thing, and MAY add a set of LED courtesy lights and a pair of folding drink holders to the back ends on either side of the drawers (I also have a "market umbrella" that is hitch mountable, so the tailgate is a good place to sit and fish, or just sit and hang out without having to mess with a full awning and poles) and I also plan on adding a set of electrical outlets (12v cigarette lighter style, and USB, maybe even 110v since I have the bed mounted inverter outlet) on either side of the drawers. I do however need to work out the design for the cargo rack first as I may need to mount to the bed floor since stake pockets are no longer an option. this would alter my side compartment design on the bed drawer system. I will also be installing several tie down points (perhaps some of that "aircraft cargo track") on the top of the bed drawer system to secure any cargo I install in the bed.
I also have some sketches I am working on for a modular cargo box set to install inside the bed where they can be accessed from the windoors. They will be able to hold tools and equipment for work, or outdoor (or photography) toys and camping gear for play my design allows for them to plug into the bed cap interior lighting circuit, and have some contact switches that will turn on some LED light strips when i open the windoor for that side. The part I am still working on designing is my mounting system. I MAY end up setting up some t-nuts in the top of the drawer system and bolt them directly in. whatever I do with them has to be sturdy and secure.
And I do not recall the brand name off the top of my head, but I plan on installing bed stiffeners ASAP... my old Ranger did not have them and I can not fit my hand through the gap between the rails and the tailgate. I can see a SLIGHT gap in my Tacoma, and do not plan on letting the same thing happen.
Speaking of awnings, I have a set of plans drawn up for making a "batwing" awning for my cargo rack. (and the same design should also work on the trailer when I can build it)
I also plan on getting or fabricating my own front and rear bumpers (I am partial to fabricating my own, but I MAY buy one then modify it as no bumper out there is designed the way I WANT. My main objectives are a front bumper with a pair of stout shackle mounts, a winch mount with hawse fairlead and a 10k winch with synthetic line, BOTH driving and fog lights, and a wrap around brush guard that is modified to be able to attach a set of brush cables, AND a set of hardware cloth screens to protect the headlights from branches and kicked up stones.
For the rear bumper I am basically looking for an Expedition One dual swing out rear bumper, though I may fabricate my own so it matches the front with locking carriers for a pair of jerry cans on the left, and a spare tire carrier and highlift jack mount on the right, but I want to modify it with a CB antenna mount on the left and a 6-80m ham radio antenna on the right. I also want to modify the bumper with a passenger side step (maybe one on each side for symmetry) as I once saw a set of strap on steps for a jeep spare tire, and am considering making a set that strap around the spare tire allowing me easier access to the cargo rack (especially when opening and closing the RTT)
plus I am planning on mounting the QDs for my OBA into the bumpers
I am also going to get a full set of skid plates from RCI (they have a good reputation from what I can tell, and are the only company I know of with a good reputation that makes Engine, Tranny, T-CASE, A-Arm, AND fuel tank skid plates. it might be a bit silly, but if I am getting a full set of skids, I would like them to be all the same brand. Unfortunately I can not get a skid for the spare tire well as I believe that MAY be a good spot to mount my air tanks IF I can protect them from trail hits. I am probably going to have to fabricate something for that.
Then for interior accessories, my truck came with the all weather floor mats so I do not need to replace them, but I do plan on getting a good set of seat covers, mounting brackets for at least 2 fire extinguishers 4 flashlights (1 for each door), 4 emergency escape hammers (1 for each door), and mounting brackets for my electronics. I do plan on getting a T-PAM for the dash and modifying it to support a second set of USB outlets (I believe it comes with a 2 outlet plug, I want to install a second one).
Other exterior accessories I am going to get a set of good fender flares... (There are few things sillier to me than tires hanging way past the fenders) and a set of weather tech window visors (I quite like being able to open a window without having it rain in)
As you can see... between work and play I have a LOT to do in building my own truck. And this does not even list the things I have been working on designing for a trailer (admittedly heavily inspired by Drifta Off Road from Australia as well as design elements from a couple other aussie brands.) The trailer will MAINLY be a mobile kitchen, as I have been accused of being a right decent trail cook, but will also be a second place to mount a RTT as well as having a propane shower, and storage for various camp accessories including my camp latrine.
As for a RTT... Yeah that is a custom DIY design as well. Though I am torn between WANTING to do an old fashioned canvas tent and wanting the lighter weight of a treated nylon tent. Each have advantages and disadvantages. but since I am going to be mounting this on a cargo rack instead of a set of cargo bars, I might as well take advantage of the space. So I have designed a custom tent that has a cargo box or optional drawer system built under it, and has provisions for connecting to heating or cooling systems if so desired.
I AM planning on a LOT of project logs here, and on youtube as I build the truck.