-- Last Updated: Jan-19-13 10:11 PM EST --
A canoe might work.
$.02 the Pygmy is a better kayak than the Chesapeake but both are huge boats.
Obviously you will be most of the motor. You might consider moving rudder controls to the middle cockpit and paddling from there or making rudder controls interchangeable from rear to middle. A rudder is recommended, pivot footbrace rudder controls are better than push/sliding style. Push/sliding style are an abomination IMHO.
Finished weights will be more that advertised.
Children/short people need higher seating position in doubles to clear decks when paddling.
Utilize kayakforum.com for building advice 24/7
Do not make bows as pointy as shown in catalog photos, that is a danger in the water and invitation to frequent repairs when ends inevitably hit immovable objects. Rounded and glassed bows don't chip through to plywood like pointy bows.