Either will be fine.
As you said, make sure your glasses fit, or get a band for them, otherwise you'll be stuck taping your glasses to your head (it works, but it looks as stupid as it sounds, if for some reason you have to do it, use clear tape, wrap around the bridge once so it won't fall off and put the tape over your forehead up to your cap) Oh one other thing, invest in some side shields for your glasses if you are going to be in surgery a lot, it is safer from a splash perspective (even though most surgeons I know don't have them, including me).
I also wear contacts, the 2-week disposables (AcuVue 2's), and find that I have very little difficulty keeping them in overnight or longer as needed although my ophthalmologist shudders every time I tell him I do this. Carry drops in your white coat pocket and definitely carry your glasses in your call bag for emergencies.