Does it HAVE to be aluminum or plastic ? I have a Pirogue that I built using plans from UncleJohns.com website. It is 14.5' long and has a beam of about 30-31" down to about 27.5" at the bottom mid-section. It is made of Luan Plywood 5mm thick and has some oak strips at mid-section for added strength. I left the wood to show through the finish. It has fiberglass tape in the seams (inside & outside), 2 coats of epoxy resin on outside, 1 coat of epoxy resin on inside, and was finished with a coat of marine varnish.
It is only 42 lbs, is a flat bottom with no keel. It will turn on a dime, paddles easily and is best for small creeks, ponds, small lakes (though I have had it out in Dallas Bay twice. It draws only about 2 inches at the center with me in it ( about 180 lbs) And it has enough rocker to make it very maneuverable. It does not leak at all.
The best way I could describe the feel of using it is: something between a solo canoe and a kayak.
If you are interested and... I will need to check with my daughter to make sure that she does not want it before I commit to sell, then I could send you photos.
I have about $130 invested and about a month of weekends in labor. I could consider selling it for $200. PM me if you need to contact me.
Gene ( Lil Mutt )