I have a CD player with a coaxial digital output and the new soundcard I have in mind will have coax digital in. What type of cable should I use for this (impedance wise, etc.) and more importantly, ...

I've got a digital TV terminal box that has a Coaxial Cable out and an SVideo out. We use our home theatre for audio (digial out) that's not the issue. My question is, what is better picture quality?