Thanks for the advice.
I'm not really concerned about originality- one of the mods is going to have to be to radius the wheelwells anyway- I wonder if any of the producers do that from the factory? It's always painful taking a sawzall to something new...
If it were a CSX numbered car, well, that's a different story. Then I'd be looking for tires aired up in 1963 to 'borrow' the air from.
Truth be told, until I joined here, I wasn't aware there were so many different companies reproducing them! I never heard of ERA (Wow! Nice stuff!). I'd pretty much only seen Superformance and FFR. And for what I want to do, the FFR seems to be the right choice anyway, since there will be a lot of 'modification' anyway. I'm still in the learning and research stage, so keep the advice coming.
Maybe one day I'll go for one that looks 'authentic'... depending on how much fun I have.