Air Liquide and Praxair are the two major canadian companies, both do cylinder exchange, though air liquide supposedly does fills too.
Apparently (?) fire extinguisher service places can fill bottles too, though you should ask if it's new or recovered co2 (recovered meaning from industrial sources, perhaps not suitable for beverage use)
Fermenting - Pomegranate Mead (3g), Acerglyn
Kegged - Modified Bee Cave IPA, Calypso Pale
Bottled - Brown ale, Pomegranate Mead, Orange Apfelwein