you can also try summit racing. i just ordered 4.55 gears for front and rear for a 2000 cherokee and bearing sets. also ordered a powertrak locker for the rear. a whole bearing set should be cheap, like $130-160 for all bearings and crush sleeve and pinion seal, it might also come with axle seals.
i used to get a lot of differential parts from crown differentials and USA standard gear, but i havent dealed with them for a while now so not sure if still in business. dont buy them at the dealer, they are the same bearing just 400% marked up