With a 3.2 GPA, I think a post-bacc would be your best bet. Why? Because the grades earn there will factor into your undergrad GPA, which is a stat that's looked to by AdComs. I agree, you will most definitely need to retake the MCAT. Now, as for which post-bacc program is best for you, I don't know. I did the UPenn post-bacc and liked the experience. The schedule's pretty flexible and classes are in the evenings once a week, so you have ample free time to spend however you chose. However, you might want to do a post-bac based on geography or price. That's where your own research comes into play.
I also agree with DrMidLife - if you retake the MCAT and score around average, you can get into DO programs without the need of a post-bacc.
Please don't apply to a Carib school.