Axiom Home Page Forums General Discussion Home Theater QS-4 or QS-8?

After much research, here is my setup:

Ascend 170s for Front L&R

Ascend 340c for center

SVS HB-10 for subwoofer

HK AVR-240 receiver

And I have decided instead of monopole/direct surrounds, I'm going to get the quadpoles from Axiom.

My question - which ones?

Room size is 13.5' along the side walls, 18' on the front and rear walls (where the sofa and TV is, respectively.) Ceiling height is 7 feet. Sofa is only 1 foot from the rear wall.

Would the QS-4s work just fine, or will I kick myself later for not getting the QS-8s? An extra $100 isn't going to break the bank, but if I don't need the extra oomph of the 8s, then I'll get the 4s. I don't listen to music or DVDs at a very loud volume.

Thanks!