If you're slitting the throat for a "kosher kill" bleed-out, you don't need a big or heavy knife, just a sharp one. I use a thin filet knife I got in the fishing-supply aisle at WalMart. If you pull the head down & to the side so the skin is taut, and find the bare spot just behind the point of the jaw, it should be easy to cut. If you try to cut through a feathery place it will be more difficult.
