Great selection for the AVR - the Denon AVRs have good features and high quality amplifiers - it will drive most any standard speakers.
Both good options - which you choose will depend on your listening preferences and what kind of speaker "sound" you like. The Infinity speakers are slightly bright (an emphasis on the high frequencies) but have a lot of dynamics (will produce loud volume levels with modest power) and a powerful center speaker that can certainly keep up with movie soundtracks. I think they have a sound similar to the entry level Polk speakers.
The Pioneers have a more even, accurate sound which requires a lot more power to get good dynamic range and have been praised by many - certainly a great deal.
I hope that you can go listen to them before you decide which to buy!
2-Ch (HT L/R): Oppo BDP-105 BD, Adcom GFP-750 pre, Bryston 10B Sub Xover, Bryston 4BSST2 / Paradigm Signature S4 v.2 (L/R), (2) SVS SB12-NSD (Subs)
Home Theater: Bryston 4BSST2 amp / Paradigm CC-590 (C), Outlaw 7700 amp / (4) Def Tech UIW-RSSII (LS/RS/LB/RB), Samsung 46” 3D LCD