Coursework at a local branch of state school will be respected. You may not get personalized advising, etc, but just do well in your courses and do the best you can on the MCAT, while doing EC's that help those less fortunate than yourself, and you should be fine. If you are aiming for T20 schools, however, I will say that some of the smaller, well-established, formal post-bacc programs (Bryn Mawr, UPENN) have very good records of T20 acceptances, though this is likely because of a heavy selection bias too. ADCOM's know these traditional post-bacc programs very well and also get to know and trust the program directors too, so their letters carry a lot of weight (these are smaller programs and the formal post-bacc program directors get to know the students on a personal level as well).