That CLC trimaran rig is pretty cool looking. IMHO... when you increase the sail area as much as you're implying, you need to beef up the other structures or you're asking for trouble. It's just not a kayak any more. Woodenboat.com sells catamaran plans that look pretty good.

There is also a book called Canoe Rig by Todd Bradshaw that you may find interesting. A canoe (this is canoe week) can become a Proa since it is a double-ender. A Proa has a single outrigger and you "shunt" forward and backward rather than tack side to side. The outrigger always stays windward on a Pacific Proa, the outrigger always stays leeward on an Atlantic Proa.

I wouldn't attempt a homespun catamaran with a large sail; it sounds dangerous.