I hope you can change your hospital - but I'm unfamiliar with the rules of HMOs. If you really want a midwife - you should go for it. It is not too late to switch to a midwife. And its odd that Rush doesn't have midwives - I really thought I heard of women delivering there with midwives. Other hospitals such as Northwestern certainly have midwives.
There's two midwives I recommend. Debi Lesnick with North Shore Ob/Gyn - she delivers at Evanston Hospital. Gayle Riedmann and Julie Marks deliver at West Suburban Hospital. Evanston Hospital has better overall facilities than West Sub - but West Sub has the only "alternative birthing center" in the area - which has a built in waterbirth tub and a full bed.
WRT to doulas - you can contact Birthways. They have apprentice doulas. Good luck to you!