You should consider the ASUS P6X58D Premium:http://www.newegg.com/Product/Product.aspx?Item=N82E16813131614
This board has USB 3.0 and SATA 6 GB/s capability. In addition, it already supports the new Gulftown six-core processor that will be available this summer. It also has great overclocking features.
Right now this board is listed at $310 on Newegg, but I have seen it as low as $290. Keep your eye on combo deals at Newegg, and I suspect you can pick it up for less than $300.
Good luck with your build.