I really must suggest that if you are only looking to connect to your receiver, you get a cheap optical converter such as the Onkyo UD-5 (opt out only), I paid ~$5 a piece for them and they work excellently. Just plug into a usb port and you are done.
KEEP IN MIND digital output uses the DACs in the amp, therefore the quality of the soundcard can be neglected.
If you are looking for something that does analog aswell, then there are a multitude of options, but all of these cost more as they need good DAC/ADC chips.
I might suggest the M-Audio Sonica (8channel) or the M-Audio Transit (2channel), I have only used the Sonica, but from this I will assume the sound quality of both are excellent. Both have digital out and therfore can do AC3/DTS/PCM. (Yes a 2channel card can output digital surround) Turtle Beach has a stamp sized optical and analog out.