As has been pointed out, it's difficult to cover everything with one canoe. If you want two seats and plan to take one or more people in it at times, that pretty much rules out a solo canoe, which is my favorite.
Regardless, shorter and wider are more difficult to paddle fast or even reasonably fast or in a straight line than narrower, longer canoes. Ease of paddling should be a large consideration. It's just no fun paddling a tub that one can't control, particularly in windy conditions and/or choppy water.
Weight is important. It's not just getting the canoe on and off the vehicle. It's also portaging it and dragging it over beaver dams, etc.
For that reason I like Kevlar. Light and strong.
If I'm float hunting out of the boat rather than using it just to get somewhere, I prefer wood and canvas. Extremely quiet, look nice, not terribly heavy ( about the weight of aluminum) and in the right design, very easy to paddle. In fact, it's my favorite canoe construction/material. I build and restore them so have one for just about any situation. They're a lot more durable than most people think.