The only way that Sony avr could be considered 1015W is vivid marketing imagination
That the Sony STR-DH770 I see advertised that way at Best Buy? The 145wch rating is likely only a 1 or 2 channel driven rating at 6 ohms maybe the 1khz rating at 1% distortion, too. I see Crutchfield say it's 90w/ch in stereo mode into 8 ohm at .09%THD 20-20kHz, which sounds more like it at that price point. In any case power among receivers only varies a few dB and isn't that important depending on the speakers you want to use. Your speakers' are indicated as 8 ohm compatible and mains 90dB sensitive, the others a little less so most avrs wouldn't have a problem driving them.
What's your sub budget? I'd not get a Polk sub particularly (and it doesn't need to match by brand)