WJs have different lower control arm mounting locations, and everything from the knuckles out is different too. The XJ axle will not work unless you are planning to lift the WJ, then put the WJ outers on the XJ axle and you will gain better LCA mounts (will require teraflex LCAs), put a XJ style front driveshaft on it, and you will be good to go.
What bearings? The unit bearings at the axle ends (near the brakes) or the carrier bearings inside the pumpkin? The unit bearings are easy enough to change out, although they can be $100+ each, but the carrier bearings will be a little tougher for someone without much mechanical knowledge to change out.