Paul, i know what car your talking about and i would do this :

Speak to TT, i noticed he has his old 3" mongoose laying about (looks like a bargain to me )

then fit a K&N filter, either cone or panel it dont matter which imo.

then get a chipped ECU and fit it.

then if its not going to be driven permantly hard get a cheap charge cooler kit for it

Then take it to "my mate" Chris @ Power Engineering and get it set-up on the rolling road and you will be looking on the better side of 200 bhp (with the right boost)