I'd say since it needs all that engine work, I would go through the entire cooling system and make sure the radiator, hoses, thermostat, fans, etc. are all in good shape. Check the obvious wiring and look for corrosion or rust. Make sure all grounds are good. Replace all fluids, fuel filter, oil filter, air filter. Check front suspension for loose or worn joints. Grease every zerk you see. Check the manifolds for cracks. Check the brakes. Reset the kick down cable slack on the throttle body. If all this is done, I'd say you have a good chance at having phase one complete.
Look around the forum for easy upgrades. Check my thread (link in my signature) for some easy things I did.
My XJ thread: http://www.jeepforum.com/forum/f177/im-back-xj-2628914