I just replaced my passenger side power window regulator. Not the easiest task, but after a few hours, a few beers and more then a few f bombs....I finished it. The original regulator was very S-l-o-w----. I opted to buy it new from an auto chain store for the warranty. Online is cheaper, but warranties and the way that they are manufactered made me wary. The track and internal arm mechanism must be close to halway down when removed and it is under spring tension too. Removing the regulator reminded me of this and damn near chopped a finger. It can be done, just be patient.
As far as going to a salvage yard for electrical components. ....Im not a huge fan. Remanufactured oem with a free replacement warranty is as close to oem as you can expect. Buying a 30 plus year old part that has been sitting in a field in a door....may only last 30 days.