Allen - I wouldnt worry about being intimidated by the banks. They want out of these things as bad as anyone, for the right price. I wouldn't worry about having a canned line. Especially if you have a particular asset you are looking at. If you are looking for a list of assets the banks have, you will have a much harder time with that, unless they have a dedicated website.
As to who the right people to talk to, that is a tough one. Since you are looking to buy the notes, you don't want the REO department. Different banks have very different ways of handling their "Special" or "Distressed" or "Criticized" Assets some banks have new groups set up focused on selling notes, others would do it through the officer managing the individual asset.
My suggestion would be to reach out to the head of commercial real estate lending for the particular region you are looking at, you could also ask for the head of their commercial real estate workout area and then try to work your way down to the officer.
One thing to keep in mind is taht these people are usually way overworked. As I said above, if you are looking for a list, you may have some trouble. If you can find some assets you would like to buy and then figure out who the lender is, your success rate will increase significantly.
By the way, I am a former Commercial Real Estate lender and workout officer who now manages projects as a receiver or as a manager for REO properties.