The strip size will certainly work, the finger joints and any subsequent skarfing to length, aren't structural joints, so as long as they stay together it is all good.
Pine density can vary quite a bit, extra ponds on the boat is a given, but how much could be from a few pounds to as much as Mem is saying. Also consider the quality of the material, is a better wood or just shipping quality .... the lower the quality, the harder it will be to work with ... since this is one of the first decisions affecting the build and it is not really reversible after you start, make sure your source material is "up to snuff" .... this is best done before you start.
Brian