I bought this system:
http://www.classicautoair.com/?q=67_..._Chevy_AC.html
I have it all installed and just need to go get it charged. Heat works great. Total with shipping was right at $1400. Vintage Air is about the same. From my internet research they looked like the 2 top brands. The rest I've seen are a lot less expensive, and its probably for a good reason.