As a nontraditional applicant, I don't think you should worry at all about taking your premed reqs at a community college. If you do well on the MCAT and do well in your courses, you will have no problem at all. I started off in community college back in 92. I went for two years, got about 13 Cs and dropped out (School was not what I was looking for). I did my thing for a couple of years (traveled, worked, 'soul searched') and landed at City College of San Fran with an intention of transferring to a UC. So, I took all of my premed reqs at a junior college, but finished out my degree at Berkeley. My grades were the same at both institutions and my MCAT wasn't bad at all. None of my interviewers had anything negative to say about my premed reqs being taken at a CC. In fact, a few interviewers thought it was a very wise thing to do (save $) and realized that as a non-traditional applicant, it was one of my only options. You may find that some schools (like the Ivies) may have too much 'pride' to seriously consider many applicants who started off at CC, but schools like the UCs do not seem to find CC inferior (as long as you do well on your mcat). Your graduate degree, your work experience, etc..will add to your uniqueness and maturity. Just kick ass in a CC, kick ass on the MCAT, and I'll see you in med school.
My verdict: CCSF gpa: 3.98/Berk gpa: 3.85/MCAT 9V/12P/11B/R. Applied to 11 schools, 6 interview invites, attended 5, outright accepted to 2 (UCSF and Einstein), waitlisted at 3 (NYU, RWJ, UCI) and then accepted of the waitlist from 2 (UCI and RWJ). I was rejected preinterview from UCD, UCSD, UCLA, Stanford, and Mount Sinai.