Kevin... If you are looking for a blue-water cruising boat and you know what you want in terms of size, rudder etc. as you state...then I would simply call one of the brokers who specialize in blue-water boats and tell them what you are looking for. A lot of these guys KNOW what is coming on to the market before it makes it to yacht world and can also advise you to consider models you may not have heard of or thought of before. I would not call them buyers brokers but you CAN rely on their knowledge and advice UNTIL you get to the "I want that boat" stage!
If you are looking for a production type boat then yachtworld is your best bet unless you happen to know a good broker that actually works for a living!!
Good bluewater brokers I know:
David Walters...David Walters Yacht Sales Ft. Lauderdale
Steve Liebowitz- Annapolis Yacht Sales
Also Deaton's Yacht Sales in Oriental NC