I don't understand why you would want a soundcard - Unless you do require it - if you don't need it, the onboard sound is good enough, you will not hear any difference if your using headphones/speakers
I would also recommend another motherboard, http://www.newegg.com/Product/Product.aspx?Item=N82E16813128506
my brother has this one and it is incredibly good for its price, and the money that you save with buying this motherboard you can sink that into a better gpu, maybe a gtx580? (personally prefer ATI, but were not building a rig for me :P)
Hope I helped.