Well I was just thinking of getting a canoe and being a skier I wanted to make sure I was not out of line looking at canoes instead of kayaks. There aren't many used canoes in the Utah area though.
You can ski and snowboard by yourself, it's not so easy to canoe by yourself.
I found that kayaking is: easy to move around on land, do when it is windy, a little easier to store. Kind of like riding a sport bike compared to a tourer.
Canoeing: better for hauling heavy camping equipment, easier to fish out of, cheaper if there are two of you, more comfortable for long day rides (my knees and ankles get sore after a couple of hours in a kayak).
Define your needs and wants, then back into the decision. There are flatwater canoes and whitewater canoes, just as there are flatwater kayaks and whitewater kayaks. There is as much variety in canoes and kayaks as there is in motorcycles and cars, maybe moreso. You're mention of whitewater tells me you won't be happy with a squareback canoe, or with much anything over 15'. There are little short kayak playboats that are great in whitewater but suck going in a straight line on flat water and lakes.
If your fishing for answers and understanding then consider the can of worms has been opened. Craigslist and REI.com are your friends in this case.
I have a Canadian made Scott canoe that is a great boat. They don't make it any more.
It is square stern, flat bottom, and has more or less square chines. The bottom is rigid and you can stand in it and fish. It will handle three adults if they are not too "canoe stupid" (i.e., if they pay attention to where everyone else is before making a major weight shift).
With a 15 HP Merc on it it will go about 30 knots. But you don't want to make any sharp turns at that speed. If you get it sliding sideways and stick a chine in a wave you're out of the boat!
It's a great boat for Maine lakes but needs a small trailer and a couple of guys of average strength if there is no boat ramp.
The How It's Made TV show just filmed the canoe building process over at Old Town canoes over in Old Town, near Bangor, ME. That is scheduled for showing an about two months. Great company and great product too.