I would advise against throwing your weapon... its generally a bad idea, in a survival situation anyway. Granted they are designed for throwing and strapping on a spear but unless you have a seperate knife reserved for still having I wouldnt do it. What happens if you throw the spear and it sticks in the animal but breaks the stick and the animal runs off? there goes your knife. What happens if you throw it and it goes in the river and floats down stream? or goes off of a cliff, or a mighty phoenix swoops down and catches it mid flight to use as nest building material
Get a good hunting knife and if you are wanting to put another blade in your pack, get a hatchet with a solid back end on it you can use for hammering. A hatchet would save you immense amounts of energy when building a shelter and also greatly reduce the effort for flint knapping some [B]rocks[B] to strap to your stick which you can then throw at your quary without fear of losing it... its just a rock and a stick and some vine or other type off cordage and some tree resin (sap).
On a side note, I wouldnt mind having a few of those aforementioned blades. I dont know how i feel about the rounded handle, i would prefer some with flat tangs on them so you could more easily carry them in a smaller package.