There are only 2 kits that I know of out there and I have built both. The wing hellcat and the old Jemco Hellcat. The jemco has a foam wing and would be difficult to fit retracts into. It is actually just a smaller version of the Wing kit although the wing kit is the newer of the 2. Jemco is no longer around and wing kits are kinda pricey.You can find the Jemcos on ebay. I have a pic in my gallery of the Wing Hellcat with a rcv 90. Good luck