I don't know exactly what middle-tier means but I think you get can a good preparation for a primary care medicine at just about any medical school. Therefore, locaition seems like a big factor to choose on where you should apply. Off the top of my head, here are some suggestions (that doesn't include the big guns but does include those that take many out-of-state applicants):
big city - Temple, SLU, Tulane, Drexel (formerly MPHU), USC, Rush, Tufts, OHSU, Howard, George Washington, Morehouse, Case Western, MCW
More rural or smaller town - U of Vermont, Albany, NYMC, Mercer, Wake Forest
big city - Temple, SLU, Tulane, Drexel (formerly MPHU), USC, Rush, Tufts, OHSU, Howard, George Washington, Morehouse, Case Western, MCW
More rural or smaller town - U of Vermont, Albany, NYMC, Mercer, Wake Forest