If you intend racing i would say save u penneys and get a italian bike, with a polini engine, plenty about second hand, is u a racing snake get a 6.2hp if not get a proddy 8.5hp if you like your food like me get a super 12hp+ yes thats more than a road leagal 125 sweet init haha.
if money is tight, origami rep is about the only way to go. plenty of boys got them they can tell you whats going to fall off in order, so at least you know what to expect

all the best hope to see you track side soon...even better on the track...