Used Canoes
If your gonna have three people in it, (the kid will get bigger) you need at least 16 feet. The Mad River Explorer is one of the best handling canoes out there. It has a mild keel molded in to help it track but not so much that it won't manuver..very Pricey though.
That said, I went to a marina that rents canoes and bought two 10 year old aluminum canoes for $150 each, spent $200(total, not "each") on some welding, (hard to weld that thin of a aluminum skin without burning new holes) the ends were worn down from beaching.. a little seam dressing and I was good to go. I've got three kids so it was five of us going each time..
Down sides to Aluminum, till you get good at it they are noisy when you clunk your paddle against the sides. And, up here in the Northwest, aluminum transmits (sinks) the cold from the water right up to your ass...course in the south that's no problem..up here the lakes and streams seldom get over 60 degrees by August..
Another up side, they are light, with a little balance help I can press one up on my lifted 60 by myself.. I'm old and arthritic..and my wife is only 5'3" so alone is the way it is if they're going up there...
check graig list for used, and paddle shops for bulliten boards with used gear.