For my C7R I've nailed down what I want to do, and no I won't be just leaving off the decals on the original body as had been implied.
It so happens that I have the body from the Foose C7 that I robbed the interior and drivetrain from for my 70 Camaro restocustom. I'll be using that body with the racing engine and chassis but its not a simple swap. The racing body is a widebody, and the chassis is a bit wider. The interior, however fits like a glove. No cutting to make it fit necessary. I do plan to have a passenger seat so I've got to cut out all of the racing paraphernalia and replace the floor where they now reside.
I'll be using the kit wheels with some tires I had in the parts box which I believe came from a Viper kit. They are the same diameter but the C7R tires are hollow, and the wheels are designed for hollow tires and have a ridge and ribs that I ground off to make them fit. They fit fairly well under the body but the rear wheels stick out about 2mm too far. I think I can massage the wheels and chassis to make them fit, but that's for tomorrow.
The pics below tell the story of where I am. Thanks for looking.