Lockers are a must if you want to do any real wheeling. A truck with a locker in the rear can often do things in 2wd that open diffs can't in 4wd.
lifts and tires only get you so far, sometimes all you needed to make it was a locker. Also consider if your going to run 33" or larger tires on that jeep you're gonna want to regear. I've driven a 94 yj (dads) w/ the 4.0/5speed with 33" tires and stock gears. That thing was so damn slow it couldn't get out of its own way and 5th gear was usless. The worst though was you needed to use low range in sand or the motor would bog down and stall.
Hes running an 8.8 disc rear w/ 4.56 gears and an electric locker now. he dosen't get stuck much anymore unless he hits deep mud.
In all I like wrangers and think they are decent 4x4's, however they require a pretty hefty investment before they are really good offroad. Atleast down in FL where you can't avoid deep water and mud.
One more thing, I've found the easist way to get the np231 x-fercase into 4wLO is to take the tranny out of gear first. Also, make sure you are NOT moving as the x-fer case is NOT designed to be shifted on the fly.
