Only the passenger side was a 2 piece shaft and it was just the shaft that was split not the whole housing. They did this instead of locking hubs to keep the front diff from spinning the front driveshaft. Later they found it ddin't make that big of a difference to have the front shaft spinning all the time so they removed it and made it a one piece design.
Any year cherokee makes for a good build up. I like the '87-'91 for the old Renix AMC fuel injection system but thats only cause I worked on it a lot so am very familiar with it. The '92+ HOs are good as well. '87-89s had a crappy 5spd tranny that had an internal slave cylinder so auto was the preferred choice for those years. '89.5 and up got the AX15 5spd which is a decent tranny. However the AW4 automatic that was offered is almost bullet proof so that would be my choice, plus you got better gears, 3.07s with the stick and 3.55s with the auto.