RE: built up wing
Don't waist your time Jeff, unless it is for "coolness" factor at your races. Which we had a guy out here in FL that built some Rat Racer mid wing thing that had a built up wing. If nothing else, it was very cool to watch fly.
All the composite NemeQ, Vortex, and Phoenix wings at the Nats were between 13.5 oz and 15 oz. And I believe all the NemeQ's were right on 3.5lbs... The heaviest Vortex might of been 2oz over? which is not a big deal. My two and Travis' two were right at 3.5lbs...
As far as strength, the composite wings are strong enough, so you wouldn't gain there either.
I wouldn't think there is anything to gain. The strength in the skins of a composite is far better than built up with monocote or silk span as well....