When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
IMHO buy a C5 and a turbo kit. You will be money ahead. If you love the C4 then do what was said above. Fab it yourself or get someone to do it for you. Good luck with that. The C4 is a challenging engine bay but it has been done many times. IT IS POSSIBLE.