I would absolutely apply DO and to some lower/mid-tier MDs, especially your state school and those with a heavy emphasis on service. That Peace Corps experience seriously gives you an advantage, IMO.
Your GPA is definitely competitive for DO and the MCAT is way over most averages. I think the highest avg MCAT I saw for a DO school was a 507-508.
SMPs are expensive & no sense wasting a year in one and losing that year of your life + year of physician income. Also, if you get that same 3.4 in an SMP, that does not look good.