I wear size 13 as well, and have tried to squeeze into some kayaks that weren't a very good fit ... but foot size was never the issue.

It is my understanding that just about any S&G design could be built as a hybrid, if you're willing to draw the lines yourself. In which case, I agree with Bob, just tweak the deck profile until the shoe fits.

One design I've considered building as a hybrid is Duane Strosaker's Point Bennett 18, but I'm a little taller and a little heavier than the "optimal" paddler he suggests.

http://www.ruben.biezeman.com/Point%20Bennet%2018/index.html