I disagree with Billy. Those components you chose look just fine. Here's a tip-when you look for computer parts NEVER judge by age alone. A component that may be outdated may be just the thing you need and nothing more. :sunglasses:
But if you look at some of the things Matt wants to do with this PC, like 3d modeling and software development, those will definitely run better and take full advantage of a dual core processor. 
Just so there's not major spurring match over this...it's very light 3D models. Nothing too major...I've done just some really rudimentary things, like my house (basically a box with pyramids for the roof). I got the software free...might as well use it.
I'd still say go for the Athlon 64 X2. You never know, you might get really involved in 3D modeling and the dual core CPU will really come in handy. If you want to save a few bucks now, sure go for the older Socket 939, but you might be kicking yourself a few years from now if you want to upgrade to something better.
I disagree. If the 939 is good enough now, why would that change?
I'm not necessarily saying that the Socket 939 is terrible, but the AM2 would be a better choice because it's more recent socket, thus it will generally have more support. But, IMO, no matter which motherboard you choose, get a dual core processor.
