dude, you're in the UK. I would reccomend for 50-65cc the leo vince for the bimatic. you can hopefully dig one up, they are on italian ebay everynow and again. incidentally, if you happen to find a source, please post it. really anything will work though, if you can find one of the straight headers and can weld. try to find pipes designed for torque, the NOI is a low reving sob.