Sorry to see the rust, but it's good you're going to deal with it before a big money drop into drivetrain. Unfortunately there aren't patch panels for those rust areas,
you'll have to make them by hand. I would start to look for a trusted body man and go over the whole body getting off the bondo, so you know what's what. By the look of what you found so far I would bet there's more in the roof gutters/A pillars, maybe the floor pans, too.
If you decide to move forward with repairs, then some of the guys here can help guide you though, in my opinion, the worst part of this sport.
@remy1974 is making some great headway in new patch panels, so keep in touch with him, maybe someday we'll have new wheel well lips.