Exhausts for a spit

["Johnny Storm: International racing car driver" <hiu06f@bangor.ac.uk>]

All this talk about exhausts has interested me in the makes mentioned.
As far as i'm aware ANSA,MONZA etc aren't available here in the U.K 
(stand by to be corrected!!). What can the brits tell me about the 
exhausts available in the U.K! As it is whatever I get it won't be as 
loud as what I have. I know about triumph Tunes and the tssc one what 
other good options are there for a LOUD (but not M.O.T pain in the AR@E)
twin box exhaust? Yours isn't standard is it Rich?????

Johnny Storm '77 Spitfire 1500