Another tool for anyone trying to size winches or any other hardware
for their boat is the Harken
CompuSpec site, http://www.harkencompuspec.com/
Select your boat from the list (assuming it's listed), answer a few leading questions about what you want to do, and they will recommend appropriate hardware
(Harken, of course) for your application. You can also view a loading report that will give you all kinds of fascinating information -- for example, just what is the load on the sheet for your 150% genoa
in 20 knots of wind
? Or the 100% jib
in 40 knots!
For my small boat (with a large foretriangle), they recommended 48's for the primary winches.