I had a Sony STRDB1070 which was rated at 100 watts x 6 channels. It was a good receiver but the amp section was very overrated as to power output. I'd say output was more like 30-40 wpc with all channels driven. I used the processing section for more than a year driven by outboard amps. This improved things. Ultimately, although I liked the receiver very much, I gave it away, and replaced it with a Sony TA E9000ES processor driven by a Yamaha M80 for the front channels, and 2 Onkyo M282s for center and back surrounds. Some of the best music and movie sound I've ever heard. I think the Velodyne sub is an excellent choice and will integrate very well with your set up. I think you will like the M2s very much, and I think your choice of Polks is also very good - IMO they are the best of the mass market speakers out there.
Good luck with your system and enjoy the music!
