I'm finding this decision a little tricky. 1. Do I add a P90 to an already bi-amped AVR300 (using 6th+7th channel)? 2. Do I add an A90 and somehow bi-amp this? To use it alone would not improve stereo sound over my otherwise bi-amped AVR300 IMO. 3 Do I use a CD36 instead of my CD192 with my current setup?