#1 81 and up had a different front end... fenders, hood, hood valence, core support, inner fenders. They will all fit as a whole package, but you can't mix-n-match as a simple bolt-on.
#2 The wiring for power doors and windows are separate for the main interior harness. So that is easy to pull out of a donor. It just plugs into the fuse block. Be sure to get all the relays and the door harness boots, window regulators, lock actuators and rods. Being a 79, your doors have all the neccessary holes and monting points. Cutting the hole in the door and cab for the wiring is the hardest part. Not sure if you can do it with the door on, but there are stamped dimples at the front of the door to help locate the drill bit.