I imagine global excursion is right, withthe short wheelbase of the CJ, you might just have to go with the gear drive 4.7 case. If you've got the length, I'd definitely go with the dual case option using the chain drive in the rear. Thats what I'm running, and I love it.
Don't forget, with either one, you have to buy an adapter plate to go from the v6 transmission to the gear drive t-case.