Hardware from the Canadian suppliers tends to be pretty expensive. I found China (health-cabin.net specifically) to be the cheapest option, and the shipping was decently fast. Getting juice over the border is apparently risky though, so I asked them to send empty carts instead of the pre-filled ones. As far as Canadian suppliers, electronic-cigz.com has some amazing flavours. Vapables.com is pretty good if you like DK, they're also the only place I've seen selling Canadian cigarette flavours. So far I've had no problems getting small juice shipments from the States (where it's quite a bit cheaper), but YMMV.
You should check out the Canada forum:
Canada Forum