More importantly, though, is how do you convert your series of cards to a usable string of bits without losing entropy or introducing bias? It is not a trivial problem.
Wouldn't a "brain wallet" be a trivial solution?
Just type: "Diamonds 8, spades Queen, diamonds Jack, clubs 3, ..............", you see my point. Type it all, no entropy gets lost, and you have a private key.
once a card has been drawn it can never be drawn again
This shouldn't be a problem, as long as you use enough cards. A full deck of cards is more than enough: 52! >> 2
160.