Personally I would go with the Denon as I own some of their products and they are really good. However, it looks like the Yamaha might be a bit more compact, you might want to check the manufacturer websites for the dimensions though. That sound card should be fine, you would just need to connect the optical output to the optical input on the amplifier. Lots of the guys in here like the Asus cards better than the Creative ones though. I believe this in their top of the line equivalent.
http://www.amazon.com/Xonar-Phoebus...8&qid=1369846479&sr=8-1&keywords=asus+phoebus