Yes they are street legal in all 50 states. This one will go 60-65 mph. There is a 75cc kit out there that boosts HP and it comes with new sprockets to boost the top speed to around 75 - 80 mph. "I think" the whole kit costs around $500, but I maybe wrong.
Akrapovic exhaust, K&N Power Comander III, AFAM 47 tooth rear sprocket, K&N air filter, yellow Trick Tape headlight cover, Scott dampner, Goodridge (Front) brake-lines