You don't mention what options your TV has but I also have the WDHD tv box. What I have done is connect it to my tv with the HDMI connector and also have my bell pvr connected to the tv with HDMI. My AVR does not have HDMI so I use the tv to do the switching. My tv has an optical out that I plug into the AVR for audio. So whatever I'm watching on the tv, the audio is output to the AVR.
Panny TC-P60GT50, Bell 9242, Yamaha RX-V730, Paradigm Cinema 70, Harmony One, HTPC