I don’t think there are official pre-med programs at all three; that said, the biological sciences, and I believe the medical school research, is strongest at Wisconsin. If you perform well at these schools, each should provide a solid chance at med school, as they are all well-respected in academia. Also, medical school admissions aren’t prestige-oriented re: undergrad in the way that, say, law or finance is. If you were to focus on bio-medical engineering, then I’d suggest UIUC, though that particular engineering focus (really, most anything to do with bio-sciences) will also be strong at Wisconsin.