There's no point in a sound card to take the load off of the CPU. That stopped being a problem back in the Pentium III days (probably before that, really).
As far as sound quality goes, any modern onboard sound solution is just fine if you're not a true audiophile.
If you still think you need one, this is about as well as you'll do in that general price range, though. http://www.newegg.com/Product/Product.aspx?Item=N82E16829271001