You said you were going budget, right? Well, if you want to save another $60 or so, you can get an ECS K7S5A motherboard for about $60 or so. Pretty good for a rock bottom price. Just make sure you get a high quality PSU 300W or higher from a good manufacturer like Antec or Enermax.
I want to make sure I get a board that serves good for future upgrades, which is why I picked a kt333 board. I don't know much about the ECS MB, what I need to know is if it will be able to support the top of the line products I plan to upgrade to in the future.
Newegg.com has the maxtop case with 3 fans and 350 watt amd approved power supply for only $47. A little noisier, but will keep your athlon cool. Also check their refurbished section for deals on motherboards and video cards.