Dana 50 and Dana 60 housings are the same size. The parts inside of a Dana 50 are smaller, comparable to a D44. I wouldn't recommend a Dana 50 unless you want that size. It is harder to get aftermarket parts for the Dana 50 but you can still get lockers, gears, chromos and all sorts of stuff. I recommend either sticking with a 44 or 60 though. A 44 has the strenghth of a 50 but better clearance. The 50 and 60 have the same clearance but the 60 is much stronger.

Jeep
Jus' sayin'