As for a list of practitioners, I know that birthnetwork.org has one, though I'm not sure how complete it is....there is another, as well...perhaps one of the mich. midwives can chime in w/the name of the list? As far as the law, I'm not sure. I think it may depend on how well your sugar is controlled, as to whether or not you'll find a practitoner to take you.
I hope with all of my heart that you find a midwife. I have SEEN as a doula the "care" type I moms get, and I wouldn't wish it on anybody... Certainly, if you are not able to find a midwife, PLEASE consider getting a doula. Birth Network also has a list, though I KNOW it's not complete. Having a doula will definately give you a leg up on having a midwifery model of care type of labor and birth, if you MUST have an OB for your primary care.