Buy a speaker selector box. Rocketfish, Monster, Pima, etc. have six pair selectors for $80-140. Get one with impedance protection and volume control so you can set things up the way you want. Only problem is all speaker sets play exactly the same sound (i.e. not surround sound). I bought the Rocketfish (RF-SSVC6 ROCKETFISH 6-PAIR STEREO SPEAKER SELECTOR) and am very happy.
Good Luck!