What is the gearing on your Jeep now? That may be the only thing you might want to change if it's geared way low. Just air down and it will go pretty much everywhere.
My buddy Tarin has a Jeep he set up for dune cruising, jumping, AND rock crawlin. It does pretty damn good, but he dumped some cash into it. He put some blinged out 22's , custom coil over suspension, moniter w/ cameras underneath for rock crawling, small block, etc.