The best way to go is a KLX 110. It has the bigger 12/14 wheels, and the entire bike stock holds up awsome! Throw on a Works or Elka shock-> (if you have the jingle) and stiff springs and dampning rods for the front, and Moto out! Trail bikes also offer's big bores and big valve heads for dirt cheap these days, then add a couple more hundred for a 26mm Mikuni carb. Dont run a china carb!
The Klx 110 is just a much easier bike for a adult to ride, you can charge harder, and be more comfortable on the bigger tires and overall larger size.
KLX all the way.
The china stuff has gotten pretty damn good though..... That bike I was motoing was a 160cc 10" 50 based bike, with + 2" swinger + thumpstar forks. It works realy well.... the power is just plain stupid for the size wheels and wheelbase.
Most people are much faster and better rider's are on the mid size bikes.... I fit in that catagoy, not riding in 2+yrs and getting back on a 10" in soft arse sand was a bad combo.... but still realy fun banging bars and holding back the bigger bikes. :woot: