Quoting Sandy:
Can someone tell me which are the best Heirloom seeds to order in Canada,
and where would you order them from?

I would suggest ordering from Tomato Growers Supply, as they are a
known dependable source among obsessed tomatophiles. They are US
based, but ship to other countries.

The only general comment that I would make is that striped/bicolor
tomatoes can tend to be a bit unstable at this time regardless of who
you order from.

(Copia comes to mind as an unstable one, for example)