I don't know to much about sound cards so I came here for help. I have about $50 bucks to spend on a sound card ( getting one for Sennheiser 598's). Here are two I found.
Asus Xonar- http://www.newegg.com/Product/Product.aspx?Item=N82E16829132020
Creative Sound Blaster Audigy SE 7.1-...