While I plan on having the most medicated birth possible :LOL I am an ardent supporter of midwives, and you'd have to kill me first before I were cared for during pregnancy by anyone other than a midwife.
As an advocate of midwives, I can tell you that these OB offices that are cropping up "with midwives on staff" are actually trying to undercut the midwife-only practices. I, personally, would not choose an OB/ midwife set up over a midwife only practice, if I had the choice, because it would feel unethical.
However, if you feel that you particular circumstances demand a different hospital than the one the midwives deliver at, you have to take that into consideration. But if any complication arises the midwives certainly have a backup OB, and could get you to the appropriate facility, couldn't they? I would ask the midwives very thoroughly what would happen if you go into labor early-- this is something they've dealt with before.
But you sound very confident you can go past 36 weeks, so maybe just trust your own instincts on this one, that you will carry beyond the dates you carried last, and stick with the midwife only practice.