We're helping a family member get set up with DirecTV. They're probably getting a Genie, HR24 DVR (hopefully) and a Genie client. They would also like an AM21 OTA to go with either the Genie or the HR24 DVR. I'm not real familiar with the AM21 antenna and need some advice... (1) Can this be added to the DirecTV order (via a phone call perhaps) or does it need to be ordered separately? (2) What is required for installing the AM21? I don't believe there are any outside antennas installed at the house. Is an outside antenna needed or will the AM21 box do the job? (3) Will an AM21 detect local channels at full broadcast resolution without DirecTV compression? Thanks in advance for the help.