Just thought I'd drop in and say that there's no motherboards on the market right now that offer outstanding performance above and beyond the rest for socket 939. There are a couple of socket A boards that go far above the rest, but I'm not aware of any for 939 yet. If I were upgrading my motherboard for socket 939, I'd buy an Abit board that had the features I wanted.
I also have to ask why you're buying a processor that good. It'd be a complete waste for gaming...gaming PCs rely way more on RAM and videocard power than CPU power. If you're gonna do multimedia stuff then I understand, but otherwise, I can't recommend spending that much on a processor. It's not that it's "overkill" or "a bit too much;" no, you'd honestly not tell a difference from a low end Athlon 64 to a high end Athlon 64 in any game at any setting. Remember, the human eye can only detect 60 FPS and lower.
Once you breach 60 FPS it's useless.