Which AC/heat system and why?

I have Classic Auto Air in my 69 Barracuda. It works great. It uses my controls after I modify them a bit. Their instructions have been updated. They used to be really crappy. If you have any questions, their tech people are only a phone call away. I put the system in about 15 years ago, and it is still working great. For several years, I told people that the system was great, but the instructions were horrible, but they have been updated. I would recommend going to the website and carefully reading the installation instructions. My system blows so cold, I have to turn it way down after a little while.