7.1 ch., or bi amp either l/r fronts or center?

Hi all....I have an extra 2 channels of amplification - 250 watts/ch (Parasound A51) available for expansion. Speakers are Aerial Acoustics 7b for fronts, CC3 for center, and B&W (in ceilings) for back surrounds. I have active Spendor's for my L/R surrounds. The 3 front speakers are being driven by the Parasound, as well as the B&W's (back sur. L/R. There is not much available 7.1 content and even though my Cary pre/proc has DPLiix and CES7.1, (both 7.1 channel output) I am not real impressed with the extra B&W rear surrounds. I will need to buy new speaker cable and y connecters to accommodate either new configuration, thus my reason for asking and not just trying.