Budget DAC Recommedations for Audigy EX soundcard

I'm looking to use my PC as a music source for my main sound system. My PC has an Audigy EX soundcard with a coax S/PDIF output. I know that this isn't the best card but I'd like to work with it before I throw it and upgrade. I plan on using WAV files almost exclusively. I plan on upgrading to a 200GB hard drive so size is not an issue (at least for music files). I plan to run 20' of digital coax cable between the soundcard and the DAC. The DAC will be next to my pre-amp.

I'd like recommendations for a used DAC in the $100 to $200 range to go with this setup. I'd prefer something on the warm, smooth and forgiving side. I'm assuming that all DAC's support the S/PDIF input. I'd also welcome suggestions for a digital cable or suggestions in general.