What is an inexpensive ac3/dts decoder?

[Stealth3si]

I have no way to pass the digital signal from my WDTV Live to my 5.1 speaker system setup because they're hooked up to my Audigy 2 that doesn't accept 5.1 input or decode AC3 or DTS!

I am looking for a "AC3/DTS 5.1 decoder" that is able to accomplish the following tasks:

Inputs:
1.) multi-channel analog input (3x3.5mm OR 6 RCA)
-OR-
2.) digital input (optical) that accepts multi-channel source


Outputs:
3.) multi-channel analog output (3x3.5mm OR 6 RCA)
4.) headphone jack (3.5mm or 6.35mm)


The "AC3/DTS 5.1 decoder" in question could either be a:

1.) PC sound card
-OR-
2.) Audio Amplifier/Receiver
-OR-
4.) Something like the Creative DDTS-100

I prefer something that is "bang for the buck."

Please recommend me specific items.

TIA.



EDIT:

The Ht Omega striker is the only one that has come up so far in my research, which seems to fit my needs.

However:

1.) I don't know if the HT Omega Striker accepts Dolby Digital and DTS 5.1 digital signal source via the TOSlink optical input.

2.) Since the "Details" Newegg page says, "Encode Dolby Digital, DTS," I'm curious that if the WDTV Live is passing the DD/DTS 5.1 digital signal sources to this sound card, would it be able to decode the signal?

3.) Will this DD/DTS 5.1 signal be processed to the analog outputs -----> speakers themselves?

4.) It does not have a headphone jack. If the software that comes with it is able to select "Headphones" as the output and mute the other output channels, perhaps I can plug the headphone to the respective output (via a speaker/headphone switch I already have.)

Otherwise, does anyone know of any other particular soundcard model or another device that can meet my requirements?

I would appreciate your help.

EDIT: I found out the answer is no for all.