Imo, and I'm no audiophile, a sound card isn't needed as most motherboards have pretty good sound onboard. As for speakers, I'm using these on one of my rigs >> http://www.newegg.com/Product/Product.aspx?Item=N82E16836121036
and I'm happy with the sound they reproduce. Audiophiles may disagree with me, but hey, different strokes, for different folks.
Hope this helps, good luck.