Funny you should mention this. I'm installing a power window system right now in my '59 Apache. I got my kit from e-bay, see:

http://cgi.ebay.com/ebaymotors/ws/e...Name=MERC_VIC_RSCC_Pr4_PcY_BIN_Stores_IT

It's manufactured by "It's A Snap" sold by 'pug191.' The units use GM motors and have large lower supports to help avoid 'wiggling.' The motor runs a sort of flexible 'worm drive' which runs a plate up and down a steel vertical track. The plate on the vertical track bolts to the horizontal support which contains the bottom of the window glass. I found that the rig worked better on my model by simply bolting the plate atop the vertical track directly to the bottom of the window frame, but that's your option. I did have to 'tweak' the unit a bit to make sure the plate kept the window parallel to the centerline of the truck. This consisted of using washers as spacers - a simple task. When I hooked the thing up electrically, the unit ran the window up and down smoothly and with plenty of power. At $130 for two units (same as the cost of two NOS mechanical regulators) I really can't complain.