if you get one from an exploder (same track width -1" and bolt pattern) they are set up spring under. you will have to weld on new perches all the same though b/c they arent in the right spot. im going to try to reuse the exploder perches (cut them off with a plasma). You will also need an adaptor, the 8.8 pinion doesnt have a yoke on it, just a flat plate. the part number is spicer 2-2-1369. u can get it from M.O.R.E for 40 bucks.
you'll have to address the brake line, emergency brakes, and shocks.
SOA is a whole nother topic. with plenty of ins and outs, and depending on who u ask is good or bad. over on pirate theres an old TOTM thread on it. also, theres a good write up on http://www.jedi.com
i have the links posted in my "buildup" thread in the the YJ section here.