I vote for the polyurethane glues (Elmers Probond). It's easy, light and the foaming action makes it very strong.

Sheeting foam wings seems to be this mysterious dark art thing....until you do it. Then you wish that all of your kits came with them. Just give it a go, you'll be glad you did.

BTW, I used this article...as from the post above

http://www.aerobatix.com/aerobatix/articles/probond/

Bob