Sail till it snows! http://www.nrsweb.com/shop/product.asp? ... eptid=1174
Kokatat is spendy stuff but it carries basicaly a lifetime warranty and their company support is TOP NOTCH.
I totally agree that a Kokatat dry suit is the best thing you can buy. If the cost scares you, as it did me, there are other options. I have a system of clothes that costs well under 400 dollars that allows me to sail comfortably, and safely into October in Canada, even on the Great Lakes. The benefit to having a variety of pieces is that you can use those pieces year round.
A dry suit doesn't have to be your starting point, there are inexpensive ways to extend the season.
But if you can swing the cost, yes, absolutely, go for it!