It sounds to me that what you are mostly asking about is if you should get the camaro or the supra. It also sounds like power is your foremost concern. If not then I would go with the supra because in my opinion is a rarer car, likely to be cheaper, and nicer looking imo.
If it IS power you want to make, the supra is practically ready to make power once u have the money, but will need a rebuild. As for the camaro, it's a bigger engine to begin with and will also need a rebuild if u want to make big power, for reliability.
Anyways, what I'm getting at, is that it's a close comparison objectively, but the bottom line is I suggest the supra. Of course, this is objective, you ARE on supramania.com after all. The weights are also similar.