I can very highly recommend Schurr Sails - talk to Hunter. He made a very sweet spinny for the 4.3. It was the best spin in the fleet, my opinion - shape, attachment points and all the nice finishing touches. He took his time in explaining to me the latest materials and colors, and the pros and cons of each. Great customer service.
Also, they just signed on as a sponsor for the Alter Cup.

Make sure you let us know who you pick and how the sails turn out.