OP: The Yamaha is not very powerful, and the Aperion package you specified has a very low efficiency. You won't get very good dynamic capability here.
I'm going to recommend Ascend Acoustics CBM170SE for all speakers (L, R, C, RL, RR, RC). This is because not only is sensitivity higher, the CBM170SE has drivers with motors of unusual capability to cleanly produce very high SPLs. They are a great monitor/HT speaker.
I would recommend two good quality 10" or 12" subwoofers, one placed on each side of room, for optimal/seamless integration to the CBM170SE units. Set speakers to SMALL, xover set to 85Hz or higher. 100 is optimal, and if you have a twin set of subs as suggested, you'll benefit doing this.
I have extensively analyzed this speaker system, and I do not make such recommendations lightly. Despite the average look, this speaker is using extremely high quality drivers considering the situation; these motors are usually only found on much more expensive systems IME. The crossover is well designed. This speaker is extremely linear/accurate. I have verified it to have about +/- 1.25dB response from 100Hz up to 16kHz. -3db is at about 75Hz. A 5 channel set up would leave you with just enough left over budget to get a couple of Elemental Designs 10" ported subwoofers. You would have very substantial dynamic capability for the entire audible bandwidth and SQ above what is usual.
-Chris
P.S.: The Ascend CBM-170SE is 4 Ohms nominal despite manufacturer specification stating 8 Ohms.