For that distance on 40 meters you might look at the military AS-2259 GR NVIS antenna. There is a modified version with coils near the feed point to bring the resonance into the 40 and 75 meter ham bands. Our club just built the modified version this week for a special event next weekend. Initial tests look very promising for 200-300 mile QSOs - especially on 40 meters. DXE has complete kits if you want to go that way.