Dunk i have a set of aftermarket rear sets for my mc18. I bought them but never fitted them as i decided to go for the original ones to keep it looking standard. I have no idea how much different they are in height to standard but the rear brake reservoir needs to be moved slightly to fit them. They could do with polishing or something as a little dull but both levers are good and on bearings if i remember correctly. Let me know if your interested.