Should I have a problem signing a contract with a realtor?

Go to the area in which you are interested. Look for listings in those areas that interest you. Call the realtors that have those listings and set up showing appointments to see their listings. Tell them you are a buyer without a realtor. At the showing interview them. Ask them a series of questions that will give you the information you need to make a decision on choosing a realtor. How long has he or she been a realtor in that particular area? How do they find their listings? What type of market analysis do they typically do to determine the sales price? Do they work with investors like you who want X, Y, and Z? Do they have investor references? Can they set up an automated search for you? 

Tell them you want to contact multiple agents to find the ideal property and you therefore do not want an exclusive representation. Show them that you are prepared to buy. You have the bank approval for your financing. 

If they find that unacceptable, move on. There will be an agent who knows what you are looking for and who will agree to your terms.