Hey guys, I lose out on a bid for a used road bike with alum. frame, carbon fork with Shimano 2300. Now, I'm on another bike. So, I found one. It's a BMC road bike but with Shimano SIS. The road bike size is M. On your opinion, do you think I should buy the BMC? I'm 16 years old, boy. Standing at 166cm/5ft3' and inseam of 30' (I think, will check again soon). How? Can I use it or is it too big? I planned on buying it as my first road bike, I want to train for next year competition.. One more thing, does changing Shimano SIS to 2300 (With STI) costly? What do I need to change it and how much? I'm not really rich, I'm still a student. TQ. Please reply.