dherk you will also need 2mm coroplast for the top of the wing. I had to order mine from a place called Pack & Seal. I had them cut the 4x8 sheet into 4 pieces for shipping. They were 2x4 sheets with the flutes running the 24" part of the sheet. They already no about SPAD builders. When I was ordering my plastic they asked if I was building model airplanes. And be patient. They are slow to fill orders.
http://www.packandseal.com/