Anyone know what bracket and associated small pieces I need to do this?

Have you seen http://www.thefirstgensite.com/html/librarydex.htm for 1st Gen specific parts?

Specifically: http://www.thefirstgensite.com/library/partscounter/illustrated/heatair/air1.html

So I bought an aftermarket A/C system from Classic Air. It comes with a bracket for the compressor. I need the bracket system that allows double groove water pump and crankshaft pulleys to be used, along with the alternator and power steering pump to use the same belt as depicted in their instructions.

That company didn't offer to help you find the right parts?