Abe,

Check out Easy Rider Canoe and Kayaks Co. They have outriggers for their kayaks and you could get some ideas from them.

Another thought would be if you had two kayaks you could put them together like a catamaran, very stable! Easy Rider has also done this.

You will not get much info off their website, (I posted it anyway so you could contact them.) but they have ads in almost every Canoe& Kayak Magazine.

Hope this is of some help to you, Ian Johnston