If I was in your shoes and didn't really know how to install a compressor, I would go to a junk yard and look around. Just about any G Body is set up the same way. Take a good look at the brackets, pulleys, belts and hoses you will need. You could take a chance at a junk yard set up but I wouldn't bet on the compressor to work. You could strip all ancillary components mentioned above and find a working compressor to complete your A/C. Make sure you get ALL bracket that you'll need!
good luck