As an aside, a 'clubman' exhaust can be fabricated to work with any engine, even if a kit works better on higher revs. I thought it reasonable to say so, regardless of your ultimate choice
Purely because some of us had little option other than make our own race exhausts, time was when the rules dictated a percentage of the 'original' remain, despite cones being added & metal took away for ground clearance. Despite such rules, Group Four (210 cc max) went well, as did Group Three (158cc Max), particularly Dave Webster's with it's very short 'U' pipe as compared to the 200's.
Nowadays, the clubman exhausts still follow the 60's/70's trend of having no greater ground clearance than OEM exhausts, but with a larger 'U' pipe with front cone.
With a little knowledge, the ability to cut metal & a friendly welder to hand, it is possible to create a useful exhaust based on the OEM item with an inch band cut out the side for better ground clearance, a cone/cones front & back & to select a tailpipe that will be spot on for the engine without creating heat build up. In addition, the last such item I made is fully isolated to allow it to vibrate freely, though you cannot see the isolation bobbins unless you have the floorboard off. I will be honest, the downside is that there will need to be a silencer, much like Gori & (I think) Ancilottis now have available. But @ least you have a choice of what form it may take & it's position. Don't forget that the exit (bleed) can be virtually anywhere on a two stroke exhaust, even half way along the main body.
Some of us do not always have the financial resources to buy an off the peg item, or be willing to accept the compromises such systems cause.
I hope this is food for thought
