try http://www.castlemarine.co.uk/pitch.htm
Just had our halberg rassy 352 redecked. Considered the synthetic option but decided to go for the real stuff. Make sure you inspect the timber...
How about being radical and putting in a lift keel?. Design it right and you shouldn't sacrifice too much on performance. Stand by for imminent...
Have to agree with Jack frost. In my opinion the engine is your most important piece of safety equipment. It will get you out of trouble more...