What receiver specifications should I be looking for?

[JSantiago]

I have 4 speakers (and am looking to add a subwoofer)

2 are Pioneer SP-BS21-LR and have max power of 80W with 6 Ohms.

The other 2 have recomended amp power of 10-80W with nominal impedance at 8 ohms.

What should I be looking for in a receiver? I have a good deal for a Sony STR-DE897 which has 100W x 7 outputs at 8ohms.

Thanks for your help

[JSantiago]

The Sony you ask about will work great.

[JSantiago]

Speakers are rated on kind of an "average" scale. 1

[JSantiago]

Speakers are rated on kind of an "average" scale. 2

[JSantiago]

Speakers are rated on kind of an "average" scale. 3