Is there an affordable 5.1 sound card with optical or composite output?

[Michael T]

I am pricing parts to build a home theater PC. I already have a decent 5.1 sound card, but it has seperate outputs for every channel. I want to connect it to my exsisting surround sound system, which has just the standard optical and composite inputs. I'd prefer a composite output, as my Xbox 360 is hooked up via optical. Thanks!
Just to clarify, my reciever doesn't have individual rca inputs for different channels, just an optical input, and a single composite input.

[kittymix]

I have my sound card hooked up to my receiver using composite RCA red/white inputs - you just need to get 3 cords that look like this (http://kaanzastore.com/ph62089.html) and plug one each into the rear, center, and side channel holes in the sound card. Then run each set of red/white inputs to your system to the corresponding areas.