If power is all we are talking about then the Sony is rated at 90 watts in stereo into 8 ohms. The Pioneer is 80 watts in stereo into 8 ohms. 10 watts is not a relevant difference in power and since the Klipsh are very efficient that difference is even less critical.
If you are not interested in surround sound you will likely get a better result with a stereo receiver or integrated amp than with an AVR. More real power and usually better sounding at the same price. More of your money goes for what you use rather than extraamps and processing you won't use.