In terms of academics and prestige, Duke and Penn are equals for premed.
But they are very different schools- location, vibe, weather, Ivy preprofessional vs. traditional college experience with big sports focus.
Premed is tough and competitive at both schools, so you all have to work very hard. They both have hospitals nearby for clinical and research opportunities.
Even if you cannot visit, try to talk to students at both schools to get a better feel.
Some students have a clear preference after a visit.