Hi ctown,
With a seating distance that far back, I'd tend to recommend floorstanding M60s, especially if you really want to blast it with 2-channel music.
The M22s with my EP500 sub will produce peak, unstrained levels of 96 dB to 100 dB SPL (that's very loud, but not as loud as some rock 'n' rollers demand) at about 10 to 12 feet.
I'd suggest the VP150 for the center, an EP350 or EP500 subwoofer, and the QS8s (you could do QS4s at the rear for the extra channels in 7.1).
As to brands, the Axioms will be clearly superior (in another class entirely) to the Klipsch and the NHT, and will outperform the PSBs. The Axioms are comparable to the expensive Stratus line from PSB.
With the QS8s, you may find yourself listening to 2-channel processed through ProLogic II in 5.1, as the ambient extraction abilities of PLIIx are remarkable, producing a much more realistic listening experience (depending on the recording) than 2-channel playback.
Regards,
