If your going to swap axle's I would go ahead and put an Explorer axle in and get the rear disc brakes. but if you want it to be a bolt in axle any Ranger axle from 93+ should work. I would find one with a L/S in it tho.
because if you buy the gears alone from the sounds of it you'll need someone to install them for you and most places charge an ARM AND A LEG to install gears. i got quoted on some 4.56's and a locker a while back and it was around 1500 iirc. way too much. that wasnt counting the front axle yet.