If I was a serious off-roader, I'd go with a diesel. Overland or strictly road traveling, probably a little larger V6.
I drove a new 392 Hemi a couple weeks ago and was very impressed with the power, response, and mileage. You can even set the exhaust noise. But it's a $75k Jeep- and, in my opinion, a Jeep was never meant to be a rich man's ride.