What sort of license do u need for these? Always wanted one
Just a regular car license.
I definitely recommend to get one, stay away from carb quads unless you enjoy spending half the time in the garage trying to make it run right.
Ebay is probably the bet place to pick one up, Yamaha raptor 700's are bulletproof and need minimal maintenance, if you do go down that road make sure you go for the 700, which a starts from 2006-2014, nothing much has changed with the model from 06, just a revised front nose fairing.
The 450r's are the base bike for racing mx, lower centre of gravity, wider, requires more maintenance though, checking valve clearances etc.