I'm currently in progress on a giant simple design 25cc weed wacker giant with a 10 foot span but I'm having some difficulties. For one is a supply issue that can be easily solved with patience with the hobby shops having the material in stock. The big one is spars. I want to construct the wing with pink panther foam ribs on a single spar, and monokoted, but sourcing the material is proving difficult. I need it to be as strong as possible, light as possible, and most importantly cheap as possible. What would be my best bet for that?