AMD systems

[Lkr]

Unfortunately, for my latest build, I didn't have the money to build an Intel system. Instead, I had to go the AMD route. Now I want to install OS X on this system, but I do not know if I should go Leopard or Snow Leopard. Which distro is recommended since I assume I can't do vanilla?
Specs:
AMD Phenom II X3 720
ASUS M4A785TD-M EVO
PNY GeForce GTS 250
4GB 2x2GB GSkill Ripjaws DDR3 PC-1333 RAM