Undergrad really has minimal impact in the work you'll put into your apps, MCAT, etc.
You can go to a better school, and be a dumpster-fire; conversely, you can go to a "worse" school and excel. Medical schools will want the student who excelled.
No matter what, if you excel anywhere you go, you can do it and get into any school you want, provided you take ownership and do what you have to do. I went to a state school not known for making more than a doctor a year (if that), graduated SCL, and am preparing for medical school after applying to minimal schools because I prepared myself adequately and only relied on the school and programs, etc. as guidance and a piece of my overall research into the MCAT, etc.
I think in-state is your best bet, as it's more convenient, cheaper, and if you do well in school it could be even cheaper in the end. Also, with regards to being away from your peers, college is great because if you don't want to see that complete tool jock from high school after seeing him on your college campus once, you probably won't! It's much more spread out if you go to a moderately sized campus. At my school, it seemed like everyone who I disliked went there, and I only saw them in passing a couple of times. Everyone's schedules change, different buildings, different halls, etc.; I loved it personally.
Hope this helped!