I straightup recommend a Razer Salmosa like stalife did. I went from a crummy trackball mouse to an Intellimouse to the Razer Salmosa for playing BW, and the Salmosa is just an excellent mouse. I can't speak about the technical aspects except for with a game like BW, older mice really don't present an issue with the game. Even in SC2, the Salmosa performs just fine.

Actually, on second thought, the Salmosa is NOT for palm-grip users such as yourself. I think the Logitech mx518 may be best for you. I have some friends who use palm grip and are quite pleased with it.