Have had Dish with HDTV package and HD offair for 3 years but want NFL package and want to switch. Have 4 receivers plus HD on one (Dish 811). I have antenna/amp/rotor and get numerous OTA channels with Dish 811. Want the best combo D box (no TIVO needed) with strongest OTA HD channel locking and multipath handling. Please suggest what I should be looking for with model numbers please.