AJ, if the Factory 5 interests you at all get on the autocross forum and ask for "Red Joker", he's the one there with the FFR and knows what it really takes. He got his car where it is I believe for just over $20k and it will out handle the 69 and likely the C5 as well, obviously it's nowhere near as practical by a long shot though.
If anything do the 69, already tons of C5's out there.