Any property listed in a MLS system can be shown by any real estate agent who is a member of that MLS. If you haven't found a real estate agent and the property is listed in the MLS, you need to get in touch with an agent and find someone you can work with who is a full time professional. If you need a source to go to in order to find a good agent, there are some good resources.
For example, http://www.crs.com and http://www.wcr.org and http://www.rebac.net These are all good places to go to get a CRS designation is not easy and requires you to take courses and prove a certain amount of closed business; this is the top designation a sales agent can get. The Women's Council of Realtors is an organization that attracts the "best and the brightest" who are full time professionals focused on improving their knowledge and skill levels. REBAC has a course of study that provides the buyer's agent designation known as the ABR. These networks are all excellent resources for finding a top agent.
However, bear in mind always that you and the agent you choose must be able to communicate so you might find that despite excellent credentials, you just can't work with an agent. Contact a few and see who you can communicate best with and go on to that foreclosure or others.