Suggestions for a new Motherboard

Two of the ram slots have gone bad/were defective so I am looking to get a new one, but would love some suggestions, I am going with amd, and plan on running two graphics cards in the near future. Here is my current build-

CPU- AMD FX-4100 Zambezi 3.6GHz (3.8GHz Turbo) Socket AM3+ 95W Quad-Core Desktop Processor
GPU- GeForce GTX 550 TI 2gb
Ram- 16G Gskill Ripjaws
HD- 1T Seagate
Power Supply- APEVIA ICEBERG ATX-IB680W-GN 680W ATX12V / EPS12V SLI Ready Power Supply With 3-Color LED
Case- NZXT Switch 810 (very large)


My budget is 400$- for the mobo, any suggestions are greatly appreciated.