Jörg,
Four people plus gear in a single canoe is a large load. Weight is not the problem. It's the people. People cannot sit for long periods of time in small spaces. Also, people do not want to sit on the bottom. They want to sit on a raised seat which will make the center of gravity much higher. So you may need a boat that is very long and very wide.
Before I would commit to this project I would rent the largest canoe I could find, put everyone in it and go for a long paddle to see if the ergonomics was acceptable.
In America we have a traditional style of canoe called a "freight canoe". About 20 feet (6.2m) long and 40 inches (1m +) or more wide. The only one I have seen was a stripper. It had a samll transom to accept a motor. It was wide enough to be rowed and very heavy.

Charlie

: Hi All

: I'm searching for a S&G Canoe serving as a platfrom for longer river trips
: Some Details: I plan a 2500km trip at River Danube (Europe)So I'll face
: larger bodies of water, sometimes wind and waves, boat wakes, portages at
: river dams and to the camp sites. I plan to take up to 4 paddlers (crew
: weight after Christmas actually 220kg = 460lb, Parents +2 kids (9, 14))+
: gear for the 2 month trip. The need for food and water is limited to a 2-3
: days quantity. I guess I need a payload of app. 320kg = 750lbs. Due to the
: long trip speed and tracking are required. As I do not intent to run
: whitewater I can live with a slow turning boat.
: I know I'm asking a lot from the ship.
: Till know I've buit a S&G Pygmy Coho and a Pygmy Osprey 13. Thats why I
: prefere S&G over strip design.

: Has anyone an idea about an available design / plan
: Does anyone know, how the Pygmy Taiga would fit to my needs

: Best thanks

: Jörg