If I could get every $0.01 back out of my WJ and start over, I'd maaaaaaybe get a Diesel JLUR, or perhaps a JT, aka Gladiator (especially once the diesel is available). That's not an apples-to-apples thing, because just the stock vehicle would cost 2x my total investment in the WJ. The WJ has a new engine (including every sensor and peripherals like coils, starter, etc.), new cooling system (upgraded larger all alluminum radiator and aftermarket e-fans w/ shroud), 242HD t-case swap (freshly rebuild, new chain, 6-pinion planetary upgrade, SYE), JK Rubi Recon Edition D44s (thicker front axle tubes and bigger Cs on the Recon) with e-Lockers (4.88s, plus lots of gussets and trusses) and a ton of other maintenance/upgrades that makes it as good, or perhaps
better than new (as is the case with the cooling system).
The JL/JT would be brand new, so everything is fresh. However, the WJ has things a JL/JT wouldn't have without spending a ton more on mods, such as coil-overs (front), 3-tube bypasses (all 4), hydraulic bump stops (all 4), front/rear long-arm with full belly skid, winch, customer beefy steel bumper/tire carrier, etc. Also, even with how much mine has grown the WJ is actually a more compact and nimble size compared to the JL, and waaaaaaaaaay more nimble as compared to the JT. The smaller size is a double-edge sword, the JL has more room inside for sleeping and/or gear, and the JT obviously gives you a real bed and tons of optionality for outfitting a rack-system and a RTT that doesn't actually have to be roof-height etc. Anyway, if I could start all over, I might just do exactly the same thing again with a WJ. Otherwise I'd be spending probably 2.5-3x the total investment to build a JL/JT to the same "level"... but it'd be new and diesel and have more space and be on 37-40"s instead of 35" so there would be advantages.
Now, if I were in your shoes I'd give the wife the FJ as a good Overlander with good street manners, then I'd build something like a 2-door Cherokee Chief for me. But I'm a weirdo. Trying to be more realistic, and knowing it's probably not a great suggestion to give your wife your "hand-me-down" FJ while you get yourself a new project, I'd probably be looking at something like a LR4 or a GX470. Outside of MPG, they're ideal DD and part-time Overlanders (if more technical crawling isn't part of your Overland plans). You can get relatively low-mileage, LOADED V8 ('09-13) LR4s in the mid-high teens, here's a perfect example:
That's the top-trim-level "Lux" with ~107k miles in the right color for an Overlander and everything.
I know, I know everybody is going to say "ZOMG NO NOT A 100K+ MILE RANGE ROVER PRODUCT!!!!!!!!!!!!!!!!!!111!111one!!!". And they wouldn't be entirely wrong that they're not THE most reliable thing in the world. But most of the horrible issues were in the Disco II/P38 era (that still used the old Buick-derived aluminum V8 and British electronics). The later stuff once BMW, then Ford, then Tatra (who made the Jaguar Land Rover group to keep running those two brands) owned them are actually pretty solid. Like any 10 year old vehicle with over 100k miles, I'm sure you'll have an issue here or there. But they're actually not that expensive to repair or get parts for, if you stay away from RR dealers. I had a 2006 Range Rover Land Rover Sport Supercharged that was honestly flawless. By contrast, I had a 2006 Lexus IS250 (aka, a Toyota) that had to be bought-back under Lemon Law. Obviously those are just anecdotal stories and don't "prove" anything, but get on the forums and you'll see the BMW-and-on era RRs are really not bad. Just think, your wife can have a high-end luxury SUV that was probably $60k new for somewhere in the teens is pretty neat. And for Overland-type duty (not crawling or "hardcore" wheeling) they are very, very capable.
-TJ