I'm just fitting an Ace exhaust from Quicksilver and the general fit and quality are OK. The only alteration I've needed to make is to shorten the tail pipes, as they stick out too far from the rear body for my liking. Also, the rear most mounting is not fitted to the tail pipes so it needs fabricating from stainless strip and welding in position.
An Ace system is also available from
http://www.cheesmanproducts.co.uk/ in the UK and they are pretty much the same as the unit from Quicksilver, they are however nearly twice the price!
Both companies only make these exhausts to order and I had to wait one month for my order from Quicksilver.
Regards Luke.