Welcome to the forum!
Running the video through your TV sounds like a good idea with your equipment. As for the audio portion, you could run other audio connections to the receiver. I'm downloading the owner's manual now to get a better feel for how to go about that. You may also get good results by simply connecting the digital audio output from the TV to the receiver - you'd select which source to watch/hear through the TV, but the sound would come from the receiver and its speakers.
I'll update this as required once I get and read through the manual for the Onkyo.
Adam