the glass isnt needed it will only add weight!! a lot ,use marine ply or birch ply 1/8 all over is ok or you can go liter on the deck but id go 1/8 for the hull .1/4 for rails and transome.i dont see the point in using glass over wood unless its balsa wood.if you do want to glass it id go the 1/16 ply for the bottom of the hull to save weight.