Dang, I'm jealous - those are three excellent vehicles! To help with a couple of questions... Going to 5x4.5 bolt pattern is easiest doing a front disc brake upgrade using 73+ parts. It's easy-peasy and there are many threads on the process. The rear end depends on what you have. It's probably a 7.25 which I believe can source LBP axles from a later A or F body. If you replace the entire axle an 8.75 is nice but spendy and is overkill for a slant. An 8.25 would fill the bill cheaper and work nicely.
Good luck with these projects, you have some really nice stuff to work on.