I ordered my Deck on vacay in the States last spring. Ordered it from American site and had it sent to a FedEx store near me as the address, general delivery type thing. You can do the same with UPS, just need to provide ID and such when picking up. You can do the same thing in Canada at FedEx pick up spots. Hope this helps.
I have no idea what a paysafe card is, sorry buddy. But I changed my account to United States and currency on Steam with no problems. When I got back to Canada just changed it back to here. As another mentioned I’d give Valve a call regarding what they process for pay. One option is going to Best Buy and buying Steam Store gift cards in roughly the amount of the steam deck. Just double check you can change your default store to Canada with no hassle because the gift cards won’t work in any other country except the one issued in. Learned that the hard with Nintendo gc’s.