Looking for a standalone digital audio decoder

I'm looking for digital audio decoder along the lines of the discontinued Creative Labs DDTS-100. It needs to take the optical digital output from my TV, which may be carrying either a 2-channel PCM or a 5.1-channel Dolby Digital signal, and convert it to 2-channel analog for input to my pre-amp.

The GefenTV Digital TV Decoder is the closest I've found, but I'd like two optical inputs and the seemingly high fault rate concerns me.

The Cambridge Audio DacMagic would be perfect, albeit a touch pricy, but it won't decode a Dolby Digital signal. The Teufel Decoderstation 5 also looks like it would be a good bet, but it's only distributed in the EU and I'm in the United States.
Looks like such devices were common in the past. Some discontinued models that I've turn up include:

Sony EP9ES
Sony SDP-E800
Technics SH-AC500
Technics SH-AC300
Marantz DP870
Denon AVD-2000
Cambridge Audio v500

I'm currently researching the pros/cons of these models.

I'm confused? If you aren't going to use 5.1, then you don't need to decode it? Correct? Even a pro logic unit with digital in should work since you only want two channel out.

What's the second optical for? Coax or USB may work better?

Also, you are probably compromising on DAC quality going for older units.

My advice: Scrap your pre-amp and get a really high quality 5-10 year old pre-pro with all the digital inputs/outputs you will ever need. They will most likely still have 24/96 processing with dual burr brown or crystal chips, remote, auto switching for signals and maybe even a 2 channel bypass. Anthem, B&K, Sunfire, Adcom just to name a few that can be had for no more than the DAC Magic.