What size tires are you planning?
How will you be wheeling? Terrain? Hard or easy on the gas?
What gears are you planning?
Budget crunched or open?
Now for bolt in axles any Dana 30 from an 92-99 xj. The 92-96 with abs have the bigger u joints. The 97-99 all have the bigger u joints.
The Dana 30 zj v8 is low pinion but has 3.73 gears.
The Dana 30 out of 4 cylinder xj and tj have 4.10 gears
The tj rubi 44 has 4.10's, locker, is low pinion.
Remember your front and rear must match gears.