I really don't hoard copper pennies (yet) but I have a huge hoard of nickels. I have a friend on another fourm who has invented a sorting machine for pennies. He is thinking of selling video of how to make your own.
Pennies and nickels are the way to go in my opinion. I'm into 90% silver coins too but I'm not buying silver now. Why should I when there is copper in them there hills?