I imported a chipper from the states. (I went and picked it up). I was also looking at purchasing a 3/4 ton pickup in the U.S. but found one locally. Here is what I learned.
Depending on which State you purchase from you may have to pay that States' tax. Most times if the item is shipped, then you do not have to pay State tax. If it is picked up, you may end up having to pay that States' taxes. (Illinois is like that, Michigan is not).
Shipping is pretty expensive, plus you usually have to pay broker fees which can also be pricey. One advantage in picking up something yourself is that you avoid these fees, plus you can examine the item before purchasing.
When importing a motor vehicle into Canada, U.S Customs require that you notify them 3 days prior to the item leaving the country (the U.S.) I imagine that this is so they can check to see if the title is clear.
Before you import anything with wheels into Canada you are best to check with RIV (Registrar of Imported Vehicles). They are the government agency that will require you to prove that the vehicle (or trailer) meets Canadian safety standards. You may even have to have the U.S. manufacture give you a letter stating that all safety recalls have been performed (if any) on that particular vehicle.
Now when you return across the border and stop at Canadian Customs you will be required to pay the GST on the purchase price of the vehicle/trailer. No duties will be imposed if the item was manufactured in North America or Mexico. You will also have to pay a $200 fee for the RIV Form 1. About a week or two later you will receive a Form 2 from RIV in which you will have to bring your vehicle to a designated mechanic (usually any Canadian Tire with service facilities) to have it inspected to see that it meets Canadian standards. I believe RIV will inform you if any modifications to your vehicle are needed. (Things like bumper heights, daytime running lights, etc.). Once RIV has received your completed Form 2 you can then get plates for your vehicle. When you purchase the plates you will also have to pay the PST on the purchase price of the vehicle.
The parity of the Canadian/U.S. dollar has made it more appealing to look to the south for equipment. The market is definitely much larger. Do a lot of research with RIV as to what will be required with a bucket truck. It may not be such a good deal if you have to make expensive mods to it to appease the Canadian government.
I ran into a stumbling block with my chipper. It came with a four digit serial number and RIV stated that it needed a 17 digit serial number (as do all road vehicles in Canada). I had to have the manufacture issue me a new 17 digit number. Bandit Industries were excellent to deal with and I was soon on my way.
Hope this helps. Best of luck.