I have to say, you can't really go wrong with either the Denon or the Pioneer, but that's assuming you're planning to upgrade in the near future. I am all for slimming down the receiver to get a sub sooner...Eventually, though, your speakers will likely do better with a more robust amplifier driving them.
Powered Zone two puts you in a whole other realm.
I did a pretty cool Denon Receiver Step Chart for bad robot you may want to check out.