Dude, for $400, you could get just about the best Athlon setup you can think of.
I recently setup an FIC AD11 with a 1.4Ghz Athlon, and the board went without a hitch. We had tried before with an Asus A7A266, and it was a big mess... I know raub likes this board, but he even had a bunch of issues with it getting set up.
I have had good experience with boards from Gigabyte as well.
And remember to get DDR ram with your new setup
