All Realtors have access to the MLS which, in turn, lists most bank-owned homes. So, to oversimplify a bit: Yes, Realtors do have current listings of bank-owned homes.
Are they reluctant to provide the list? Not that I know of.
Are they reluctant to show the homes? That's a slightly tougher question. Reluctant may not be the right word. Some agents know that there's often more hassle involved in transactions involving REOs. And they know that sometimes the banks pay reduced commissions. So: More work for less compensation. Let's say some agents aren't too enthusiastic about showing them.
However, a buyer's agent represents the buyer. And the Code of Ethics contains various guidelines on how the agent will represent his/her client. So any Realtor should not only be willing to show any home the client wishes to see, but to fully assist that client if he/she wishes to make an offer on the property.
And, frankly, there are many Realtors who focus on foreclosures and have no reluctance or hesitation at all. So if you've talked to an agent or two and gotten the feeling that they're not going to commit 100% to representing you, keep searching until you find an agent who will represent you. It shouldn't be difficult.
Hope that helps.