[Arran]

It doesn't really matter, most U.S vendors will sell and ship to Canada. There is also a fellow on fleabay from Quebec that does sell veneer from time to time, I've never bought from him but he seems to sell for reasonable prices. Realistically you have to get over the hangup over cross border shopping with this hobby, I hate to say this but Canadian businesses are still largely clueless about selling online. But then again Canadian businesses are largely clueless anyhow, many are not only economically illiterate but mathematically illiterate as well.
Many Canadian businesses still have not caught onto the idea that the U.S and Canada is an integrated economy where they don't have to limit their market to a country of 34 million people. They whine about people cross border shopping but still insist on buying from Canadian middlemen suppliers at a markup when they could buy off of a U.S (or China) one for less and pass on the savings. I don't know whether it is a case of ignorance or a misguided sense of loyalty, most of the Canadian suppliers and distributors are just buying off of U.S ones to begin with. Entrepreneurship seems to come to Americans much more naturally whereas Canadians tend to play useless games like picking and choosing who their customers are.
Rather then caving in and using the wrong materials just because a Canadian retailer has a paltry selection I would search a little longer from one that does have it, or buy off of fleabay, or go to a U.S supplier. If they don't really want your business take it to someone who does, the Canadian dollar is worth $102 U.S right now so why not. As for Mohawk products they do have a Canadian website, so if you contact them they should be able to put you in touch with the nearest retailer of Mohawk products.
Regards
Arran