broad question. how about some more info on what you wanna do with the jeep, how big of tires do you want, what kind of wheeling if any are you going to do. it will be a good time for a lift, spring over is a good idea to think of to. 87-90 xj and mj had rear d44's rarely, they are a good swap, also ford explorer 8,8 rear ends from late 90's are a good fit.
the front doesn't have a direct swap in, i'm building dana 44's from an old scout but my front axle will be right side drop for a d300 t case. lots of options and variables, and the sky is the limit.