From the last shot, I can tell that he is using Viper/Ghostrider's latest version of F2003-GA shape. Just a slight re-positioning the poly at the engine cover to make it straighter and extended. Can't really see the changes he made on the rear endplates. And textures, looks like Bojan's one to me. Hope I'm wrong...
@Keiran
Not bad for a first timer, but yeah...your blue and green is too dark. Work more on it and I'm sure you can make a good looking C23 livery.