I have to think it's unlikely to be the most cost-effective swap (even having the ZJ already), it's far from the best HP per dollar option, and it probably isn't a common enough swap to have much documented about wiring and whatnot, but if you're down to try it, I'm down to follow along! The transmission length may be an issue with your driveshaft length, but lots of variables will affect that. From what I know the later ZJ V8s are at least reliable-ish? At least it's not a WJ 4.7!
Are you unhapy with the 4.0 currently in the CJ?