I love that you're putting a lot of thought in. I think physical cards with actual gameplay elements might set off some concerns about anonymity. I know a lot of guys don't want their address recorded anywhere, so if there are gameplay options they just can't have without physical cards, they're probably going to sour on the game.
There was discussion over a year ago, of doing silver 1oz bullion bars of each of the different cards. That's the kind of direction I'd like to see them take, personally; although that might need to wait for a few more players to arrive.