everythigns possible mate ,

theres at least two zetecs in the uk with over 500 hp , both lads frequents this site, im sure they can help with specifics regarding prices ,

as for 700 hp .

could be done , if hes running it on race fuel and fuck off hugeeee turbo , slam a bucket load of boost through in one spike ,

it will make the numbers , but may not be useable ,

see what you can dig up over the pond fella

try searches on the web ect , if its a tuner it my be on youtube ,