About to have a s/s exhaust ( catless I think ) and air induction kit supplied and fitted....Graham Goodes quoting £1150 plus VAT for their own system which I beleive is top rate ( any comments ) and Demon Tweeks quoting £625 inc VAT for a Catless Mongoose system and pipercross induction kit! the scooby is a 00 sti vers 6 standard just having had it's first 1000 mile service. Do I need to be looking at other alternatives or are any of these OK ?