I've never had a processor fail, but I have had MBs fail. But there's no guarantee since the PSU died. No telling what happened to the voltage when that happened. But if I had to guess, I'd say it was the board that took the brunt. This may be fate's way of telling you that you need to upgrade to a new CPU/board/RAM.
But if you still want to try your luck with a new board, AM2/AM2+ boards w/DDR2 are pretty rare now. Your best bet may be ebay for a used or possibly new one. However, Newegg still has this one: http://www.newegg.com/Product/Product.aspx?Item=N82E16813157274&IsVirtualParent=1