Silver Wheaton (SLW)
Purchases silver at a set price (ex/ 3.20 per oz) and resells it at market price. Costs will stay the same regardless of silver price. Relatively unaffected by external factors (labor prices, etc).
I believe that silver will rise in price.
Pan American Silver (PAAS)
COEUR D ALENE CP (CDE)
Completely dependent on the volatile price of silver
Financials (From Yahoo!)
Market Cap: 2.35B
Div (Yield): None
Disclosure: I own shares of Silver Wheaton