What's a good sound card with at least 5.1 channels, that supports windows vista and is like $50 or less.

The onboard sound on your motherboard...

Seriously, less than $50 isn't going to get a 'good' sound card...one that is actually any better than the onboard. It is because the onboard audio has improved that much, that the low end sound card market just isn't.

this is the montherboard i will be getting,
EVGA 780i sli

Yeah...it has 7.1 HD audio...so unless you want to spend over $100 for a sound card, stick with the onboard.

thx alot for the help.