I belive the pair stacks are just two individual cables. Someone who has purchased these might chime in, or you could ask Outlaw before purchasing. So with the 3 pairs you are saving a few dollars and will only have one extra cable. On the other hand, with the 7 pack you'll have two extra cables that you can use somewhere else in your system, such as replacing the the audio RCA's on your DVR. Or if you're going to use the DVD-Audio, I believe you need 6 cables with RCA plugs connecting the DVD player to the 950, so you'd be 1/3 of the way there...

It is more important that video and the coax digital cables are "75 ohm...for both composite and component video applications, but also for digital audio interconnections." But you don't need silver. When my 950 arrived I grabbed a spare RCA cable and I'm using that for the digital coax out from my DVD player. It's still sucessfully passing the digital signal.