Your car is going to look pretty sharp. I always liked Dove Gray, and with the T-tops I like it even more.
Magnum GT is right, a good fender won't be hard to find, and will be a lot cheaper. The old saying is there is always somebody who will fix anything for enough money. But, I don't think any body shop would attempt that one. I know it may not look too bad, but the metal is too badly creased where it was hit, especially around the wheel opening, and it can never be pounded out right.
You can also try Pick 'n Pull, Pull-a-Part, or other salvage yards. It may be too far away for you, but I checked on line and Pick 'n Pull in Dallas has a 79 Cordoba in their yard. If you have a good body shop you can ask them to find you one. My experience is that they have sources for parts us motal men will never have.
As for the a/c, you might want to start a new thread to get more people's experience. I spent a lot of time on it last summer and still don't have it going. To make a long story short (which I can go into detail if you want) I had it working great for three days until it finally blew out the suction hose about where the arrow is in my pic. The hoses and tubing are unique and I can't find anybody locally to fix them. I ended up putting it off because by then it was late in the summer last year and I had too much going on this year to mess with it yet. I will probaby have to have hoses sent to Classic Auto Air because they can weld steel tubing for new fittings.
Don't get the receiver/drier can from Autozone, or wherever they sell the Four Seasons or Murrary brand. They tried twice for me and the part number they have for it is the wrong one. I went with RockAuto and got the ACDelco one, and it is right. I got gasket and seal kits for rebuilding the RV2 compressor at
www.centuryautoair.com. Some stuff is also available on ebay.
Keep plugging away at it and you'll have a good car.
P.S. Make sure the fender mounted turn signal indicators are working. For some strange reason that impresses the heck out of the young guns.