Thoes 5.9L are sought after. If its not in too bad of shape I would clean it up and start adding power. I wouldn't take it out and beat it too crap. but heck it would be nice to have that power on the trail.
Jeeps are kicka$$!!!! Get it man! My cherokee has 210,000 miles on it, my TJ went anywhere, I beat the hell out of it and only had to replace a couple radiators. Suspension is MUCH much better than our ranger suspension.