i have seen an STS kit on a C5. looks like alot of work to install. it runs the returns on each side over the rear wheels through the rockers and to the TB.
if you keep an eye out you can get used headers for our car for cheep. i got LPE stainless ones with an X-pipe for $300. they had a crack in them where the bracket is on the torque tube.
clay, have you looked into the LT4 hot cam, heads and intake yet?