You are buying from Canada?
Paypal will only allow cards to be used as backup for their accounts that are valid in the buyer's country.
So if you live in Canada and are buying from Canada, you need a Canadian Visa card, Canadian address, and Canadian bank account.
If you have a US Visa card, you need a US address and a US bank account.
Sellers can only ship to your Paypal address to retain their Seller Protecion, so it should match your eBay address.