Since some of the more knowledgeable members haven't chimed in, I'll take a crack at this one.
I'm not an expert, but the rear window regulators should be the same from 67 to 69, the front regulators for 67 are different from the 68, 69. The wiring harness should work the same, but there may be minor differences in wire length, routing through the doors, and how they connect to the fuse panel. The window switches are the same for 67, 68, but I don't know about 69. BTW, the correct switches have rounded corners, not sharp corners. Many GM cars used the same switches. I've always assumed that the switches mount in the same place that the window cranks do. There are a few vendors offering power window conversions that bolt right in, but the switches are usually not correct. The internals are of course not the same as factory, but who cares since no one will see them. Besides finding an original complete set is next to impossible and will cost you alot more than going with aftermarket stuff.
hope this helps. good luck.
