I've placed the order for the new quarter panel from Auto Metal Direct. The cost was significantly higher than I would've paid from Rick's Camaro or Classic Industries, but I believe I'll be getting a much better part in the end. This quarter is supposed to be the original gauge metal, and they claim that they've done extensive fitting and development of the parts. We shall see.
One complaint I have of the floor patch panel from Rick's was that it was noticeably lighter than the original steel. It's a fine part, and there's no reason to redo the repair, but just something to note.
I think I can repair the inner wheelhouses myself with some simple patching. I'll have a couple weeks to wait for the new parts, which should be plenty of time to clean and prep, and make that repair. If this works out, then cost to repair the quarters will be a hair over $1200. Which still leaves the roof. Expensive! But still cheaper than farming it out.