Wow. I have been just using good ol' Radio Shack "TV" wire for SPDIF. Short length of course. I guess though from reading this other stuff that the nice EXACT digital copies I have made from my Marantz CD Recorder to my Lynx One card are all messed up since I didn't use expensive cable.
Okay, sorry about the sarcasm. Old school for me you know!
You need 75ohm cable for SPDIF wiring. I can almost assure you that those very expensive cables you buy at home stereo stores, and probably the Monster too are the same stuff that you can buy at Radio Shack! Really!!! I can assure you that if you buy a short length of it and solder your own RCA connectors to it that it will work flawlessly and will be a whole lot cheaper than these other products. About $12, and you will have a whole bunch of cable left over to move your cable box around with....
Now, if you are needing AES/EBU wiring, you need a 110ohm wire. Most decent quality three conductor cable will do the job.
I am serious. I will buy that for mic to preamp applications that expensive wiring will give you benefits cause I have heard it. Same with quality speaker wire. Even interconnects in the studio can benefit from good wire. With digital wiring though, as long as the wire isn't totally whacked out and messed up, and is rated to pass the signal, you will have no problems. Those advertisements for the expensive digital cables that tell you that your data stream will get messed up unless you use THEIR cable is pure marketing hype. Of course ANY 75ohm cable is going to be better than a cheapy RCA cable for digital connections, UNLESS you are travelling only less than a foot. But you DON'T need expensive digital cables to pass a clean signal. I have read studies about this stuff, and usually the consensus is that regular ol' "TV" cable (or cable TV cable) will work just fine for lengths up to about 12 feet provided that the cable is in good repair and the connectors were soldered properly.
Save yourself a few bucks and head on down to Radio Shack.
Ed