How short are you?
Your choice of bikes is all over the board....Do you want a motocross bike or a trail bike?
I'd suggest a trail bike such as the WR250 and the CRF250X even a CRF230.
A trail bike will have a headlight, and wide ratio transmission compared to the motocross bike = no light and a close ratio transmission. A light makes a HUGE
difference, my bike didn't come with one and thought i'd never need one. I was wrong. I ended up retro-fitting a light on to my bike
Personally I would never buy a bike from the dealer, unless I had money to blow. If your in no rush to purchase, winter time is the best time to buy a bike for cheap. Cruise craigslist with cash-in-hand and wait for a deal.