I used to be an Onkyo guy too but I have noticed the brand has slowly gone downhill in comparison to the other big players. Onkyo still makes some nice receivers but I hear more people complain about their Onkyo's going out than any other brand.
Personally, I can recommend 2 receivers, as I have owned both.
The Pioneer Elite VSX-60 $649
The Pioneer Elite SC-61 $1100
I mention the 61 because it can be found on sale, I just bought mine for $849 after haggling with the Magnolia guy. The new Elite line has a few benefits, mainly the new amp designs. The 60 will really push some fantastic sound through your Polks, and it comes with the latest version of MCACC.
If you want a receiver that will set you up for the forseeable future than the 61 is a no brainer since it comes with a D3 amp. Finding a D amp receiver under $1000 is hard enough, let alone Pioneers newest D3. I'm running the latest MartinLogan Motion series speakers, and the 61 pushes wonderful, warm sound through my 5.1. I have not talked to a single professional installer that has anything negative to say about Pioneers new SC line.
If you plan to stay with 8 ohm speakers than the 60 would be the way to go, even though it produces 90 watts per channel. Plus the 3D pass through and air-play are nice touches. Lastly the the Pioneer processes the low frequencies much better and cleaner than the Yamaha line, if you are considering that brand as well.
My 2 cents.