Well I've read the first few pages so far, that rear system is HUGE! I think you could accomplish similar results now days with a single PC (micr-atx) and a nice CPU and one of the eyefinity cards. There are eyefinity models that can do 6 displays. Also he used 6 separate sound cards? If you have one of the PLUG capable sound cards couldn't you do 4 or so 2 channel zones with each separate output? Seems logical as windows see's these as different ports now?
Edit: Hah just read the next page and someone mentioned the Eyefinity setup, but he didn't seem to sure that you could run 6 displays off of it and just thought it was for panoramic modes. But you can run 6 displays separately rather then in eyefinity mode.

