I was intrigued by the title of the post, but disappointed to read that it was about cabling. I believe cabling can make a difference, but as has been said already, not as much as the components themselves. If the title were posed as a question I would have definitely said the room. That also can make a HUGE difference, and I'd look to investing time, effort and $ there before exotic cables. The potential for the room impact is far greater than cables IMO and in my experience. As far as the cables themselves, IC's before PC's. Source (to pre) first. That'd be my approach anyway. Clean, isolated power will have more bang for buck than just sticking in an exotic PC. If you pay an electrician to run a couple of isolated lines for your system, depending on your house, it may run you less than many fancy PC's, and, again, bigger bang-4-$.