Some fantastic advice from all of you. Thank you!

Looking at my situation from the 2 prevailing angles: "Budget" and "Short Term vs. Long Term Satisfaction", it seems that the M80's would be a nice initial purchase, would fulfill my needs for "short-term satisfaction" within my budget, and also would provide the backbone to a larger more robust HT system with the 500, QS8's, etc. In short, they would get the job done and some.

@sirquack: I will definitely do my due diligence on the Onkyo. Thanks for the advice. If you have a better fit for an AVR in my price range, please let me know. I have no allegiance to any brand and would love to hear some other suggestions. Thanks!

@Mojo: Would you also suggest running the M80's in Phantom Mode as suggested by Sirquack and Hutzal, until I add the 500 and then the 150 and QS8's?

Thanks again everyone for the quick advice. You guys rock.