If you want a hard case
www.innopocket.com will ship direct from Hong Kong, otherwise Piel Frama will send leather cases direct, my personal favourites :)
www.pielframa.com
For batteries look for the Lion battery ad on the front page, they sent me a standard Dell including shipping to the UK for less than 1/2 the cost of ordering it over here.
You might be able to pick up some screen protectors from a photography shop, I got some whilst i was waiting for the ones i had ordered, not the greatest but they did the job.
my only other thought is try somewhere like
www.expansys.com they might have a Canadian store or possibly a trader on Ebay.
Hope this helps