I am a member of http://www.REObroker.com, that has some of the top REO listing agents in the country. If you would like to contact me, I can give you the names of some of the agents who do most of the REOs in this area.
I also agree with the guys on this one. Your best bet is to find agents who specialize in the foreclosure market and see how to get into their circle of contractors!
One other source that you may want to try is to get qualified by HMBI. Thier website is http://www.hmbiweb.com and they have a place to learn how to become a contractor for the HUD foreclosures.
Best of luck to you with your business!