My family went through a Jeep phase at one point my dad, brother and I all had older CJ's. You will not find an easier vehicle to work on. Wiring harness is what 10 wires ?
In my opinion the perfect engine for that setup is a V6 gas or 4 cylinder diesel. With the gearing in that beast plus low range you would be able to climb a wall ! Short wheelbase is great for off road but twitchy on the highway. If you are interested in the Jeep but not the engine/trans offer him 2,000.00 and see what he says. Have fun.