Anything to do inside the doors is a PIA.
You will need the motors, the door panels complete, the wiring harness for the doors, and the wiring harness that goes from the door harness to which ever fuse block. The older X's went to the inside fuse panel and so I understand, the newer one go to a relay in the engine compartment fuse block. (that is what I have been told, don't rely on that)
If you are going to go through the hassle of putting any electrics in the doors, you may as well do the whole thing, but working inside the door is a real pain, you will need good light and a mirror.
I suggest you take a mirror, and go to the ASY and remove a door panel and look inside to see what you are going to have to do.
No matter what you end up putting in the doors, you will need part of the wiring harness, and if you are going to take part of one take it all, much easier in the end.
Note: the window motors are riveted to the doors, take a hammer, and punch with about a 1/8" pin on it and drive the center out of the rivet, (the centers don't come out real hard, so be a little gentle when you hit it). Then use a drill with a 1/4" bit to drill out the rivet.