Where is the STOP THREAD button? The questions and answers are going backwards.
and if I do get accepted, do these programs have good track record for future admittance into med school? Can I apply during the same year?
Good SMPs have good records. Good SMPs are difficult to get into. Good SMPs review you as if you're a med school applicant, not an SMP applicant, thus a solid MCAT has to be in the app they review. Good SMPs fill up quickly after apps open as early as October (
last October).
Again, you are already late for SMP apps, and you cannot make plans around a fictional MCAT score. So you are not in a position to choose the best SMP. You are in a position to throw a hail mary pass and hope for the best.
In your shoes I would put everything into getting the best possible MCAT score so that you don't have to retake it. If that means you're not ready in April, then postpone your test date. You already know you're not getting into med school on the traditional schedule (which is now the minority schedule, as average M1 age is 23-24).
edit: and also, if I'm also considering doing a post-bac, would it matter for me which one I get into? i.e. WashU vs CSU Hayward (CSUEB). Because my concern is, if it does make a difference, then I'd probably go for the more "prestigious" names right? If not, I rather stay near near home in the Bay Area to save money on cost of living.
You lack basic understanding of options after receiving a bachelors degree. "Postbac" is a useless word: it describes any coursework after a bachelors has been granted, from med school prereqs to piano classes. If you are talking about taking the MCAT and doing an SMP, there is nothing at WashU or CSUEB for you. Those schools have structured programs for students who haven't taken the prereqs yet. You need GPA redemption or "academic enhancement".
You also lack basic understanding of application cycles. Good academic enhancement programs open apps nearly a year before the start of the program.
Honestly I think you should spend the next 7 months getting real world experience, paying rent, killing the MCAT, and wrapping your brain around how people get into med school. And in October you'll have some maturity and you'll be ready to apply to a good SMP.
Best of luck to you.