wot ever yer do dont bother with a 125 they are so slow its not worth it even 200 s are only as quick as a slow 125 bike
but they can be moded to be quite quick but then they dont last long
200 s are a better starting point becuse disc front + dampers on forks much better ride
if yer gettin a 125 to save on first cost its possible to put a 150 barrel on n then bore this out to 175