My advice when buying either bank-owned or short sale property is to have LOTS of patience. It CAN take a very long time to get responses from the bank, (2 weeks sometimes, for a counter offer, 30 days in one case, but 1 day in another..) and they don't do things the way any of us are used to, but you can get a great deal.
I would be more than happy to help you in your search. One of your first concerns should be to catch all REO properties that hit the market within your parameters. If you contact me directly at email@example.com I can set up a property minder search alert that will send everything your way daily, with price adjustments as they happen.
Have a great day,