If you want "bolt in" power windows you need to find a donor truck and rob the motor/regulator assembly along with the door harness, and the sub harness that goes from the door jamb to the main harness. Installing anything in your doors is no picnic, but that should be the easiest way to do it.
There is one company that I know of that offers a kit that is specific for our trucks. It's offered by A1 Electric Automotive Accessories and can be found here-
Look inside
You can also do a generic kit like the one installed in my 77. Roger at
Stoked Out Specialties has had good experience with the kits from
Specialty Power Windows so that is what we used. Since I wanted a factory look, he installed thier kit along with the factory power window and locks switches.
Here is an old post I saved on the subject that has some good info-
Look inside