How about a baidarka. I built a version of the Lowie Museum kayak LM2-14886
Plans here: http://www.arctickayaks.com/Lines/LinesAleutLM2-14886-18.pdf
My mods were to up the deck by an inch or two and to kick the side chines out a bit to to give more stability.
Pics of mine here:
http://dbynoe.blogspot.com/search/label/Sage
She is not bad for speed, cruises loaded easily at about 4.5 knots, and can sprint up to 5.5-6 with a bit of enthusiasm (she pushes up a pretty damn big bow wave at that point) and I have like zero arm strength.
I am 6'1" but pretty scrawny at 180 or so and find the boat tippy until I add about 20-30lbs of ballast (I use water). The more shes loaded the better she handles. Will a full load of camping gear I can take pretty big white caps broad side with no worries.

: Well; I'm nearly done building my son's 14 foot Great Auk, I've got
: plans underway for my wife's 15 foot Chuckanut (she's deathly
: afraid of water and wanted a VERY stable boat), and I'll start
: on my North Star plans next winter (not enough time left anymore
: this winter for build without eating into our short summer
: season). So......that leaves me without a kayak for this summer.
: I'm thinking I can probably build myself an SOF right along side
: my wifes Chuckanut. Please help me decide on a design by
: offering likely candidates. I'm a big guy (6'3" and 260
: with size 13's; but on a slimming trend......). I'll use the
: kayak mainly on lakes and rivers, but will also likely head out
: onto Lake Superior on occassion. I think I'd like to test my
: rookie kayak skills with something a bit on the "racy"
: side (for a beginner), but those design type seem to be very low
: volume and I'm not sure I'd fit into them. Any ideas out there
: for a happy medium between eoungh volume for a big fella, but
: also a bit sleek and testy?