You are probably better off having them bond the body and rivet the panels in. It will save you a lot of time and work. You can also avoid the pinched fingers while trying to rivet a panel way back in the rear fender well.
Although, if you want the satisfaction of putting the ENTIRE car together, bond and rivet yourself. This way you can get pictures of the bare frame without the body.
Definitely get the frame and suspension powder coated!!!
Glenn