Just found out I'm preggas in Hamilton, advice?

Congratulations! Unless you have something particular you want (like a home birth), I thinkt he most important thing is that you trust the midwife and can get on well with them. So have a chat about your ideas about birth etc, and see how you click. In my case, I'm very middle-of-the-road; keen on as natural a birth as possible, but not against medical intervention if necessary, so most any midwife would have suited, it came down more to who I trusted and liked. (I'm with Kirstin Rouse, if she's on your list).

Don't worry about the birthing center too much at this point. I think most good Hamilton midwives can do both birthing centers and the hospital, even if they're based at one or the other. Check it, but I wouldn't let it be the deciding factor for me. I had both my babies in Riverridge, but Waterford looks nice too.