PSN card stock fluctuates daily. I don't have real-time inventory, but here are the reliable, current sources for Canadian PSN cards (CAD currency, region-locked to Canadian accounts).
Canadian PSN cards ONLY work on Canadian PSN accounts (CAD wallet). US cards (USD) will fail redemption on a Canadian account. Ensure your account region is set to Canada (Settings → Account Management → Account Information → Residential Address).
For instant access: PlayStation Direct or Amazon.ca Digital. For cash/gift: Physical at Shoppers/7-Eleven (no ID needed).