I find it somewhat disappointing that your midwife would be disapproving of WHOEVER you had at your birth! It's YOUR birth, you should get to have with you whomever you darn well please - isn't that one of the benefits of having a homebirth, lol?
ANYWAY... I am a doula hoping to attend my first birth later this month (at a birth center) but I would absolutely support mothers who choose a homebirth. Why wouldn't they? Doulas have no legal liabilities at births (though some post partum doulas do get liability insurance), so why would they be worried? Seems silly to me! I personally think it'd be nice to assist someone at home.
Too bad you're not in LA, I'd love to do it!

Oh, a suggestion, try contacting a doula trainer in your area from DONA or ALACE. They will know of all the new doulas in your area, and you may find one of them to be more open-minded or at least eager for their first jobs (like me!). A doula in training should also be MUCH less expensive (or free) than a fully certified doula. I, for instance, have decided to offer my services for free until I'm certified, in exchange for the honor of attending births AND the family must be willing to fill out the little bits of paperwork DONA requires, and to ask their nurses/doctors/midwives to fill out the info, too.
I really think you should be able to find a doula at a lower cost, especially since you are in a larger town, as long as you don't mind a newbie. The doulas in my training group with me (15) came from a variety of backgrounds - nurses, mothers who had miserable births, mothers who used doulas for their births and were delighted, child caregivers & preschool teachers who wanted to branch out, nannies who wanted to specialize in post partum care (there is no certification exclusively for post partum doulas, they all have to be birth doulas and then just DO pp care), maternal health care majors at college etc. We all loved the processes of pregnancy and birth and new families/babies.
I would say no one goes through doula training (at around $600) just to fool around. Plus, it really doesn't pay very well - you can't load up on clients, you'd hate to have two in labor at the same time; so most take clients 3 weeks apart at the MOST. That means $350 for 3 weeks of work. Not much, eh, when it's broken out like that.
Also, make sure you get a doula who has attended at least the training classes OR has previous experience. My training was great in that it gave me techniques and a "cheat sheet" card of suggestions for various types of labor.
Good luck!