I'm making a 20.5' double paddle canoe that is really just a double kayak with a modified deck. You could set up your cockpits any way you want. There are lots of advantages to using an proven design and then modifying it to suit your needs. Maybe enlarge the forward cockpit into a cargo area with tiedowns and a tight-fitting cover. Make the rear cockpit fit really well so you could roll; also give it deep legroom where you could sleep if necessary. Just a thought.

- Chip
http://www.ChipSandresky.com