I'm certainly no expert on power windows, but power locks on the other hand, I do claim to know a thing or two...
Just to throw out my advice, on a lot of cars (not sure on these or not) there is a "5-wire" setup to control the locks. Which means...if the main component of the lock system (usually the drivers door switch) is unhooked, the rest of the locks won't work. I can only assume the power windows may have something similiar, meaning without the drivers door power windows, the rest probably won't work either...
You can probably hard wire in a switch somehow (if there isn't a simpler solution I don't know about, again, this guys no expert on PW) you will want to watch out for one thing. I do know on PW the biggest problem is limiting the switch, as in telling the motor when to stop applying power once the window is up/down. If this isn't done correctly, the motor will burn up quickly. This is one of the biggest hurdles of adding PW to a car...