As you can see below, pretty much any agent can search the MLS for active listings meeting your criteria. However as you are likely to realize once you are in the middle of the purchase process... the really valuable thing that a Buyer Broker brings to the buyer is experience, the ability to negotiate, and their skills in educating the buyer about homes, areas, condition, inspections and repairs. You will want to shop for a buyer broker who is open and communicative, who will listen to your concerns - and advocate those concerns to a successful outcome. You will be best served by a Broker who keeps you in the loop and navigates the process for a fair and equitable outcome - keeping your liability low and your satisfaction high. And, here is the most important part, closing that transaction on a good, safe home for a good price in the end!
It looks like one or two of the agents who responded to your question earlier made an honest effort searching for you. If I were you I would call them and have a discussion. Let them know what you want and what is important to you, and see if their area of expertise and communication style seems to fit your lifestyle. Almost everyone starts off shopping for a HOUSE, when really they should shop for an AGENT. I hope this comment adds perspective to your quest.
Best of Luck!