Going thru SPI you can get either a Malossi sport or a Polini Corsa BBK for under 200.00. If you just rejet your carb you can get a much stronger take off, and 3-5MPH better top end.
You can build up in stages... Pipe/carb, then get into the CVT, then perhaps an intake set up.
I ran a steady 50 on just a malossi sport, and a set of gears. Added a Technigas pipe, and Delorto carb for 55MPH, and 60 top.
Glad it's running.