Dr. Christine Brass-Jones does VBAC. If you would like a midwife, Brittani Hamilton does VBAC, as do the Bethany midwives.
I would also really recommend registering on the Arizona Birth Network Yahoo! group - you can post questions about VBAC providers there. There are lots of VBAC providers out there, but I don't know all of them. You can also post questions there about the different hospitals' VBAC policies, etc.
http://health.groups.yahoo.com/group/phoenixbirthcircle/
We also have a great ICAN (International Cesarean Awareness Network) here in the valley that meets monthly.
Blessings!!!
P.S. Additionally, the AZ Birth Network holds monthly meetings around the valley to discuss birth-related topics; they are tons of fun and are very informative:
http://www.azbirthnetwork.com/monthlymeetings.htm