Stoneman - Your stuff is already so much better than mine that I am probably not a credible source.
But, my opinion is, if I were you, I'd just keep the Yamaha, route the digital video directly to the TV, and get a nice, macro-capable Universal Remote (like the MX-700 or a Harmony or something) to make your switching easier. Unless you have I/O shortage problems on your TV or something. Seriously, the Yamaha is a good piece of equipment, and I just don't see how your quality of picture or quality of life is going to be meaningfully improved by the additional expense. You know, there is a difference between "converting" and "scaling", so just be sure you're getting what you think you're getting by spending all that time and money on cables to chase the 1's and 0's around.