Almost any PCI sound card will likely have this, since they have to offer something over the basic AC97 setup on a lot of computers. Just look for the optical plug, which is pretty distinctive.
You will also need a program that supports SPDIF passthrough for audio, so might want to check your video player of choice to make sure that's an option. Otherwise you'll want to add a new video player to the list of things you need to look for.