Using a broker is a good idea, it helps you to zero in what you really need. He also helps you to negotiate the price for you, less emotion form the owner. A good broke can keep thing very objective. But a good broke is not easy to find. Some indeed a used car salesman. So interview them and make sure he or she can work well with you and understand your needs. Good luck.
I am old school. Integrity is to do the right thing even when no one is watching.