You could have the harnesses in your ZJ now. Look under the seats for the plugs. Depending on your trim package, the wiring my already be there. My ZJ had cloth to start but already had power, so I may have been lucky to start.

If you don't have the plugs in the seats, you'll need the wiring harnesses. However, it does sound like you have the harnesses in your limited, so you'll really just need the time to swap them over with the help of a wiring diagrams...

 

Here's a copy of the FSM with the wiring diagrams in the back. I also highly recommend when your swapping the harnesses over from your limited that you swap the whole harness. There is a section on harness and connector locations in the back after the wiring section that show you where the harness connectors are so you can just pull only what you need. It will be a PITA the first time you pull the seats, the plastic moulding and the carpet; however, it gets easier.

You'll likely have to pull the seat belt anchor bolts. These are a trash-able item. The dealerships always put in new bolts because the part is crushable. Meaning they wear out and deform every time you put one in. You'll get a second or third use of them but it is wise to try to replace them if you can find the correct bolts.