depending on the riding your going to be doing your bike choice can be quite different, here in nc we really have a choice , lots of good trails and lots of good motocross tracks, your size makes your choices more challenging, for real beginners your size and xr200 or kdx200 is a good choice, if you start slow these bike have loads of performance for trails of light beginner (practice) motocross, you didnt say how old you are, if your still growing (have large people in your family?) these bikes will still carry you well up to 200lbs. but may not be competitive if your going to race, motocross brings you more into the 100cc- 125cc bikes bikes, i never want to see a beginner on a 250 even though your physical size you could ride one, the power and speed of a 250 tends to cause too many injuries while trying to learn, alot of people are having fun with the pit bike thing, but if your trying to improve your skills your going to have to go a little bigger.