First I would say buy a 1st Gen Toyota. I have and '82 and my bro has an '88 Comanche. No comparison, Toyota Wins despite having alot less power. If you go the XJ route, look into an AX15 Tranny built be Aisin and get yourself a Toyota Gear Driven Tcase. Don't use coils. Swap in a good set of leaves and ditch the Dana 35's.
I would definetly avoid the AX-15 the AW4 is a lot more reliable. Also a toyota transmission but a lot better then the manual. Also going leaf spring front is alot more work then some would imagine.. Nothin wrong with front coils, just make sure your steering isnt all fubard and youre fine. I DO agree about ditching the D35:D