I haven't built any SOF kayaks, but I have the Morris book, the Putz book and also Wolfgang Brink's book on Aleutian SOFs. I think Putz strays furthest from traditional construction, but his beamier boats with larger cockpits may be just what you are looking for. You owe it to yourself to read his book before you start building. Even if you build something completely different, you won't have wasted the time. He is quite an amusing author.