Either will prepare you fine. I took Calculus-based (my school only offered Calc-based). There won't be any calculus on the MCAT, but despite that, I still think Calc-based physics will be better preparation. Honestly Calculus-based is supposed to be harder and will reinforce your math skills (I swear, doing derivatives for electromagnetism helped my algebra), so in terms of better preparation (not necessarily better grade, mind you), I would say Calc-based is where it's at.