Welcome, and you were told right. This is the best forum on the net for your A body. There are herds of experts to help you get your car sorted out.
Thats a fine looking 4-door, and it looks like it has good bones. And it comes with a cool story.
If it was mine, I would start with the electrical and get to the A/C later. The inop heater could be as simple as a blown fuse, check there first.
Did the previous owner keep it up well? If not there will be some safey related things to check out.