And your fortunate, no T tops, they where one of the weakest points on this generation of Camaro. For those areas that you can't get at from the back side...would you have access to a uni spotter, or a pin spot welder. If not, "Harbor Freight" has been known to sell them for around $100.00....again, more outlay than you hoped for but would save you time and energy, not to mention the quality of the finished repair. Filler would work....I wouldn't recommend it...just to much filler when roughing it out properly is within the realm of possibility. Your car for, all intense and purposes is going to be painted Black. The amount of forgiveness you'll get with not straight body work is minimal. Damn this stuff gets costly but the car does look sound and worth the effort and investment.