what size dirt bike should i get?

[icedude]

i have been looking at bikes and i just grew alot so my old 90cc bike is way to small. i am about 5'7 and 185 lbs. i have been told to get a yz125, yz250f, but when i loked at a 250f it looked like way to big and i know the yz 125 is about the same size so i was leaning toward something along the ttr 230 or xr200 but i dont know what to get because i dont know if the others will be to big. and i will not be racing very time i ask someone that is there first question. so any hepl or suggestions would be great - thanks