what size dirt bike should i get?

[icedude]

i am looking to buy a new bike but dont know what will be to big or to small! i am about 5'7 and 180 lbs i just had a huge growth spurt so my old bike is way to small i was thinking about a 2-stroke 125 but when i looked at it it looked very big and i dont know if i could ride it, but the 4-stroke 125 looked a lil small because i might out grow it very quickly, the other bike i saw was a 4-stroke 230. i need help if anyone has any suggestions!! of what would be the best bike for me -thanks