The DirecTV box will serve as the tuner / HD source. Though if it is not an HD box he will need to upgrade. The only need for a tuner would be if he currently gets/uses the local broadcast channels with an antenna. Even if he later wants to be able to get local high def signals over the air, he can just get an external HD tuner. Those should not be too expensive these days at all.
Other dirty tricks they pull.... They'll intentionally adjust the settings on lower-priced units so that they look bad. And they'll give a digital feed to the high-priced units while they give an analog feed to the lower priced units. This is so that people will see a dramatic difference in quality in the high-priced units and buy them instead of the lower-priced units (which may be able to deliver just-as-good quality if properly adjusted and configured).
