The relative difficulty of the two classes can vary greatly based on the school and the teacher. I’d ask around in your HS.
In terms of overall schedule rigor, the top tier colleges want to see the guidance counselor check the box on the recommendation saying you have taken the most rigorous course-load available at your HS (which doesn’t mean taking every AP class – there is often some latitude in this). If the guidance counselor says that your prior and current HS schedules are sufficient to get that most rigorous box checked if you take Honors Regents Physics instead of AP Physics 1 then you should be fine.