Welcome Billy, for theatrical viewing and ease of switching I'd run component video from the sources to receiver to TV and digital for audio. In addition for general TV viewing when the full audio setup isn't necessary, I'd run the DVI to TV with stereo analog for audo.
I'll try and get back on the speaker situation. How big is your space, dimensions?
The Infinity system might work ok in a small apartment, but if you're looking for something more robust to enhance your HT experience you might consider upgrading. If it's an option then provide a budget and speaker constraints and we'll see if we can help.
