RZ,
I'm not an expert, yet IMO I believe the only taxes you have to pay on an "American Truck" are the state sales tax when you register it. The other problem is you can not buy any vehicle that is not at least 6 months old. As an American you can not go to Canada and buy a new car on the lot, this is to protect the American dealers from everyone crossing the border.
If you try to buy a car or import, like a toyota pick-up you have to pay some obscene amount of taxes/tariffs when you cross the border. There was some sort of trade agreement with the US and Canada on large American made pick-ups, Farm equipment, and personell vehicles that waved the tariffs.
What you need to do is hook up with some dealer who goes up to the Canadian Dealers Auto Actions(I think there is one in Calgary) and have them pick you up a nice truck, then once you get it change out the odometer and go.