From Mike (by way of Kevin Hoegen):
I added all power items aftermarket, saved money and works great.
I added the following:
Power Windows - www.a1electric.com - $250.00
Power Door Locks with Remote Entry - www.partsexpress.com (Got OMEGA DS-2 DOOR
LOCK Actuator's)
Installation was very easy if you know car electronics.
From David Medeiros:
I did this conversion on my 91, using used OEM parts. Wiring isn't too bad if you get wiring from your same year. You need the in-door harnesses as well as the connectors and such from the underdash harness. I removed the underdash wiring, which is integrated with many other circuits' grounds, and isolated it into it's own harness then stuck it in my truck. However, I had a different year harness. If you got the same year, you could just remove yours and add the other one, although you might have to remove the dash. Not a big deal, but it's time consuming.
The OEM parts bolt right in utilizing previously unused holes. I'm not sure about aftermarket kits. They probably have the disadvantage of how the mechanisms mount, but the advantage of a pre-wired, plug-in type of harness. Whatever you do, get a factory manual so you have the wiring schematics.
I did not replace the door panels. The electric door/window switch is in the same place as the manual window crank. All you have to do is make some marks and cut a big, square hole. By the way, you might as well add power locks since the door/window switch is one unit.