I've been dealing recently with Ed Whiteaker (
Whiteaker Yacht Sales in Bradenton, FL). He doesn't specialize in catamarans, but any broker can show you other brokers' listings. The key to me is find someone you can trust, and someone who will spend the time needed to help you find what you want. I think Ed will do just fine in both categories. He has a great reputation--never heard a negative about him.