I too prefer short strips, 8 footers are fine. The sheer I also find nice to have a full length strip and if I can't find a board that long I'll make long scarfs on that strip only. Otherwise I butt join the strips, the strength is in the glass skins the wood is just a composite core, though a stiff one.

Most wood's work, but you can end up with a pretty heavy boat if you're not careful in the wood selection. Cypress is considerably heavier than western red cedar for example. Not much fun having a 70 lb. kayak to haul around.

Bill H.