Which speaker would work the best as rear surrounds in a 7.1 system composed of M80Ti, VP-150, QS-8 (side Surr), and ??? Rear surr. The room is 14 by 25 feet with the system components on one of the 14 foot walls. There is no room on the rear wall for QS-8s. The system is powered by an Onkyo TX-SR800 with a SVS PB1-ISD Sub.