Ok I have my 950 going into a B&K 5 channel amp. Is there a way to use my Onkyo A/V reciever to power the additional 2 channels? I am currently
powering rears and just wanted to try the surrounds to see if it would be worth purchasing
some monos as Gonk suggested. I just don't want to outlay additional cash when I'm not sure.

Room size is 16x23 and I am using Polks all the way around. thanks in advance.....

It's not a great arrangement, but you can connect the pre-amp outputs to an analog stereo input on the Onkyo. There are a few concerns. First, assuming the Onkyo has bass management, you'll want to set the mains to "large" and the speaker distances to 0 so you don't get any extra crossovers or delays in the way. Second, you'll need to set the Onkyo's volume to a volume level to an intermediate position and leave it there (this setting may need to be tweaked during channel calibration). If you do decide to stay with 7.1, I'd strongly consider picking up some proper amplification for the extra two channels.