Help me purchase a solar system for my class c.

Wow, you have a lot to learn,.... you have it all planned out, but its not gonna work.
Drop the A/C from your equasion, and start over.
Your first idea......some solar to save running the generator so much, was a good idea.....throw about 300 watts on the roof, see how it goes. If you forget any use of A/C or anything else that uses a heating element, you will be fine.