If you haven't looked at the
AAMC list, it might be of use though it looks like it might not offer the option to sort by deadline. I think that the PostbacCAS list does have deadline information, but not every postbac will be listed depending on if they use the system for their applications.
If you're interested in a fairly structured program that will also give you the flexibility to apply now but start in the fall, Penn, Harvard Extension, or Berkeley Extension might fit the bill? Penn seems to have a few linkage agreements, and I've heard mixed to positive things about the program overall. I'm speaking with more familiarity with career-changer programs though, and it looks like you might be in a different boat since you've been through a med school application cycle already, and I assume you have all your prereqs done. Either way, best of luck!