As you probably know from the Epoxyworks article, Serendipity and Puffin use a factory built kevlar Bell Starfire canoe for the hull,cutting down the sheer, then adding a strip built deck. Plans do not exist as far as I know, but I have been told there may be plans or a kit for a stitch and glue version sometime in the future. I've been considering doing something similar using a stitch and glue hull, the Kipawa II designed by John Winters. To me, the real challenge would be to come up with a good sailing rig, since I don't have any experience with sailing.
Richard