I'd get an Asus with the 590 chipset, newegg, ASUS M2N32-SLI Deluxe Wireless Edition AM2 NVIDIA nForce 590 SLI MCP ATX AMD Motherboard - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16813131011 . Sells for $169, and $7.14 for 3 day shipping. I have the 570 chipset version socket 939 from a previous build. Even if you don't use the wirless still worth getting having the mobo