I'd stay in the MD programs...I found it really difficult in certain fields as a DO applying to rotate in allopathic hospitals and applying to residencies, especially if you want to do the San Francisco Match. Some allopathic programs tried to charge 1000.00 to me to rotate at their hospital. I had the excuse we have DO residents, but your school isn't LCME accredited. I would stick in the MD program in the US and if you want to learn OMT, just do that fellowship for MDs in OMT. I thought I wanted to do Primary care, but after 3rd and 4th year, loved all the subspecialties rather than straight IM. But to give yourself the most opportunity, I'd stick where you are...plus you'd waste a year and just incur more debt. I also been told at some top programs that "they were still old school" and have not taken a DO in the past and don't plan on it anytime soon, but the secretary said, check back in a few years. On the other hand, there are plenty of other top allopathic programs for residencies that welcome you with open arms as a DO.
I do love being a DO however, to be honest, if I were in your shoes I wouldn't switch, you'd end up in the same place with less debt. You'll be a good primary care physician no matter what, its just if you read or not. Your degree won't impact anything, just do more FP or IM rotations 3rd and 4th year rather than all the specialties.