What Jeff said above, if you're planning going FI soon, don't waste money on HFC, they will be burnt very quickly.
In terms of HFC, Berks are very popular around here.
Another factor to consider, test pipes will create a bit of raspiness, unless you go for more expensive ones like the MOtordyne ART.
You can have a look here to see what else is available:
http://www.torqen.uk/88-test-pipes
http://www.torqen.uk/86-high-flow-cats