You seem to be in a situation similar to where I was in undergrad. i have no W's on my transcripts, but quite a lot of C's, including a few pre-med requirements. I finished with a 3.2, and a 3.0 science GPA. I got a 34Q on MCAT, but I knew my chances weren't too good for med school. I am now in my second year of my MPH. i needed an MPH program that has science classes built into the curriculum, which Yale has. my GPA here is around a 3.8 here. I have had 3 interviews and one acceptance so far. I have still not gotten interviews a lot of schools, but its a relief to have 1.
It just seems that I was in nearly the same position as you, so I just thought I would let you know what I did. and on my last interview, the interviewer commented on how he thought it was good that I didn't do a post-bac to make my numbers better, but instead, got a degree that would help serve me in the future. But I think that was just his opinion, because I know that a lot of post-baccs have really high admission rates.
Anyway, good luck with whatever you decide to do.