Contact Delta T Systems. They specialize in engine room ventilation and are now working on smaller boat systems. I don't know if they would have anything suitable for a sailboat or not.
Also check out newer high quality yachts in your marina to see what they are doing. You should be able to get a good idea of what the "best practices" are from looking at these boats.
http://www.deltatsystems.com/page9/page13/page13.html