I think you would need to start with the door electronics to see if there is a connector for the power options. If yes, not such a hard thing to do...if no...you may need to swap in a wire harness for the options in the doors...like speakers, windows, locks, and mirrors.
My 96 did not have power mirrors, locks, or speakers but there was a fairly complex set of wires running to the kick panel. The wiring inside of the door was actually only two wires...not even sure how the overhead light was activated when the doors opened but they were on a separate harness that fed the rear cargo lights, seat belt chimes and a few other things.
So...I'd suggest pulling the kick panel to find out how many wires go to the doors first...then find the wiring diagram for both years to see if they match up...