I've got the 2" Hazard Sky Lift on mine. And since this discussion is always so much fun in the KL groups, here's what you need to know:
Regardless of what you choose, the KL lifts (minus Dobinsons, I'll get to that in a moment) are all exactly the same, they just add more, or less, frills. The rear lift is always accomplished using spacers, a single one for the MFC lift, two for the Hazard Sky lift. The front lift is always accomplished using a knuckle drop, which doesn't add any pieces to the vehicle, it's just re-positioning the knuckle by moving it further down the strut. Both are made in the US, both from locally owned small businesses. Both use Aluminum (Hazard Sky also offers a UMHW option to save a little money, and no, UMHW doesn't degrade, deteriorate, crack, fall apart or whatever). The only real difference between them is the rear space, in that the MFC, as I said before, uses a single spacer on the bottom, where Hazard Sky uses two spacers, one on the bottom and one on the top of the spring.
Functionally, the ONLY difference between Hazard Sky and MFC lifts for the KL is "Do you want to spend $180ish for the Hazard Sky lift, or $500ish for the MFC lift, that does exactly the same thing, using the same materials".
On the KL a lift does not allow you to run larger tires. The largest tire size you can run on a KL is the same whether you're lifted or not. This is due to how the KL is designed. And on the KL you won't be running much larger than 32" tires. You can squeeze 33s in there, but it's tight. The tire sizes that work are: 30.5" max without doing the pinch weld modification. 32ish with the pinch weld modification. Again, the lift on the KL has no bearing at all on tire size.
The other option for the KL is a spring lift. Dobinsons is the only real game if you have a Trailhawk. If you have an AD1 setup (4WD models that do not have Low Range), you can use Dobinsons or also Eibach. The Eibach kit only lifts an AD1 to AD2 height (the AD2 sits a bit higher than AD1 models). The Eibach kit will not lift an AD2 or ADL (Trailhawk) model. The Dobinson's is the only spring lift that will give you any more height on AD2 or Trailhawk models.
You can combine the spacer lift and the Dobinsons springs (I'd avoid the Dobinsons struts, personally, I've seen at least three sets of them explode in the last year on friends rides) to get a max of about 3" of lift on the Trailhawk over stock Trailhawk height. Personally, I won't go more than 2". 3" accelerates joint/boot wear on all four axle shafts, and anything more than 3" will void warranties as well as destroy the joints, the suspension wasn't designed to handle that steep an angle on the shafts.
Now, you'll also see lifts from Rough Country, Tuff Country, American Trail Products, and maybe some others. I don't recommend any of them. None of them provide decent customer service, all three of those have bad reputations in the KL community. One of them had really bad corrosion issues and was showing a lot of rust (used steel for the spacers) after only a few months. None of them actively participate in the KL community, beyond selling things for money. The owners of both Hazard Sky and MFC are active participants in the KL community and have been since the early days, and that carries a lot of weight with me, personally. Ryan Young (Hazard Sky) and Jesse Drew Lambros (MFC) are great guys, very knowledgeable, and very responsive to their customers and always go above and beyond with customer service.
As for other mods, what are you looking for? My 2015ilhawk has:
2" Hazard Sky lift
30.5" Yokohama Geolandar G015 tires
Gobi roof rack
Gobi Ladder
Foxwing Awning
Rocky Road Outfitter super sliders
Amazon Chinese Special pillar lights
Amazon Chinese Special 21" grill light bar
Amazon Special bumper mount for said cheapo light bar
Anzo 4 channel Wireless light controller
Yeah, I cheaped out on the lights, but they make dark places brighter and I'm only out about $10 bucks each if one goes bad. I'll eventually invest in decent lighting from Rigid, but I have other things I want to spend that money on first.
The aftermarket for the KL is pretty limited, because Jeep markets it mostly to Soccer Moms (despite the Trailhawk). For sliders, your limited to Rocky Road Outfitters in the US and FrogFab in Canada (and there may be one other US one I'm forgetting), but I know some people who've had custom sliders made in a fab shop. Ryan at Hazard Sky is toying with making sliders, but the costs are pretty high to produce, and shipping them is a nightmare. For bumpers, the ONLY option, outside custom fabricating, is the weird looking tube bumper that MFC makes (I think it looks weird, an honestly I question just how well it would stand up to a collision, but his full on pre-runner does at least improve the KL approach angle, and his other one is a nice take on a brush bar. For racks, those are pretty universal, but Gobi makes a really nice full rack for the KL.