Are you talking about doing it yourself? This is not a job for a shadetree mechanic you realize?
If you're asking what are you going to have to buy to swap gears and have someone install them, then the gears should come with a kit for the bearings and seals needed. I'd call for estimates in case the bearing and seal kit is extra. Additionally, if your running the 4.0 engine, you'll likely have 3.07 or 3.55 gears stock. Which means a new carrier will be necessary. Buying a Detroit or ARB locker means you won't need a new carrier since they are full carrier lockers.
If you're running a 4 cylinder, then you've got stock 4.10 gears. Changing from 4.10 to 4.56 is not even a half turn on the driveshaft difference and in my opinion, not a very effective cost to performance ratio. In other words, don't bother cause it isn't that big a difference.