DirecTV does offer 1080p, it's just charged for on a ppv basis. In a similar setup (DirecTV HR24-500, Onkyo HTRC370, Samsung PN59D8000) I let my tv do the video processing rather than the AVR (after trying both ways, looked better without the AVR's processor), and check off all possible formats on the DirecTV settings. Hope that helps.
"I realize that somebody playing free music isn't as commercial as a hamburger stand. But is it because you can eat a hamburger and hold it in your hand and you can't do that with music? Is it too free to control?" - Don Van Vliet (aka Captain Beefheart) discussing commercial success in the music biz