what are your plans for the future of this truck? daily driver? offroader? (please don't say winter transport)
as stated above, complete 4.0/auto XJ will give you a pair of 3.55 geared axles, t-case (and shifter) and a front driveshaft. you'll then need a 4wd AX-15 trans and a rear driveshaft. make sure the parts you need are in good shape before buying a donor rig. car-part.com might help with your junkyard searches.