Exhaust help required

Hello All
After some advice - my mk1 gti is requiring a new exhaust. It has a standard (i think) system on it. I need a new one - I'd like to maybe nudge up the performance with a better exhaust but dont want a fat loud thing - anyone any ideas? - or do I stick to a standard one? - if indeed they are still available?
Even better - if anyone reading this lives in Chesterfield / Sheffield area and can recommend a supplier I'd be double happy.

Cheers

Andy

Buy a Jetex

Jetex Exhausts Ltd

Tail pipe looks like