You have to be very persistent in trying to get in with banks. They usually have people that they have woked with for years. A suggestion would be to also try companies that handle more than one bank. This seems to be easier to do, then you have a proven track record to show the bank.
I started with the banks that I was doing short sales on and kept asking everyone I spoke to who handles their REO's . One company finally caved and gave me the name of the servicing company and now I am doing a few for them.
Whatever you do, make certain that the lender your buyer uses is able to process the loan without any surprises. Late closings kill REO deals.
I've financed many of these types of loans for Investors in Oklahoma properties and some of the horror stories I've heard serve as warning enough.