Scooter exhausts are normally model specific because they are usually one-piece systems and will have to have the correct mounting points. Unlike motorbikes, you can't just buy a silencer/muffler off the peg for a scooter and make it fit.
I have to confess that the Honda Lead is a strange candidate for a sport exhaust, and I'm not sure that a specific alternative is currently available. That aside, tuning a 4 stroke scooter like the Lead (especially an air-cooled one) is an expensive way to achieve little or no gain. The best way to extract more performance is simply to get a bigger and more powerful machine.
