Just a thought, check out the following web listed in the link. It's a guy named Wes Boyd who hosts a site for what he calles "large" paddlers. Regardless of the cockpit issue, you may find some other useful info there.

I agree with Jay, though. Your height and weight aren't that unusual. I know a guy with HUGE feet (like 14's) but he weighs under 200. His feet are a far bigger problem for fitting into boats than your weight should be.

Tell him Rick Sylvia sent you - not that it will get you anything, but what the heck.

Rick