RE: Flying Wing-Glass ship
Why not vacuum bag the glass and kevlar over a foam core? Making a hollow molded flying wing using plugs, seems like a waste of effort, especially in that size wing.
As for airfoils, most flying wings use some reflex in the airfoil. There are a whole class of airfoils specifically designed for flying wings, so don't just just any airfoil. Also consider what you want the flight characteristics to be like. Do you want a slow easy flyer? Good combat plane? Fast flying? Aerobatic? These need to be taken into account when choosing your airfoil. You might start by looking at existing foam wings you see flying and find one that has flight characteristics that you like and copy it.
Read up on flying wing design here:
[link=http://www.twitt.org/]The Wing is the Thing[/link]