I have a 92 YJ. It has a mild lift and 33x12.5's. I want to take it to the next level. I'm thinking SBC, 700R4, full width one ton axles, 4-link coilover, 100"-110" wheelbase, 2"x 10"-16" coilovers. Rather than doing this piece by piece over years, I'm wondering if I could buy a complete donor vehicle (maybe a '89 ck3500 regular cab short box) pull the engine, transmission, transfer case, driveshafts, and axles. Then design the 4-link geometry based off of the donor vehicle wheelbase. This would be far cheaper than buying all the pieces individually, everything would bolt together without custom adapters, plus aside from the suspension all the parts would be cheap and easy to find wherever they may break. Anybody have advice, or see any reason this wouldn't work (aside from being above my skill level)? What would a good donor vehicle?

I would look for a mid 80s to early 90s 3500 SRW one ton Chevy. It will have TBI 350, 700r4 and I believe a 208 transfer case. You can switch out to a Dana 300 w. Novak or AA adapter kits. This will also give you a Dana 60 front w 14 bolt rear. Most likely gears will be 3.73 or if you are lucky 4.10. But, depending on you tire size, I would re gear. The 14 bolts hangs low, so you will need to run 39 or bigger IMHO. Locker for the front and weld the rear unless you have money for that locker too. I wish I would have gone along those lines in the first place. Would have saved myself a ton of money. No pun intended. Good luck.
P.S. May want to look at Govt Surplus. Get a 1 ton 85-86 Chevy for $2000-2500. Only thing is it has a diesel and TH400.