You aren’t very clear if you are talking about true potato seeds (TPS) or seed potatoes. In case of the latter, it probably wouldn’t be legal to post them. Most countries don’t allow the importation of potatoes without special permits.

In the case of TPS, they may not be available for these types of potatoes, I’m not sure, and these don’t grow true to type so would probably be more interesting if you were breeding potatoes.

This probably isn’t what you wanted to hear, but maybe someone else reading this will have ideas where you can get these in Canada somewhere.

I hope you find them somehow!