I have always relied on local aquarium stores. And most of these plants were acquired in the late 1990's, and reproduced regularly. I would certainly never order plants from outside Canada, as the delays at the border are very lengthy, if they even allow the plants through. Works the opposite way too, sending plants from Canada to the US. Invasive plants is a big issue these days.
Finding aquarists with plants to sell/trade/give away in Canada may be your bst option. See if you have a local fish club, there are two in Vancouver for example, and I bought my chain swords there in the 1990's.