You can use most of the latest DHzer0point releases since they should all support the 6800GS. I would say just go with our latest, the 84.43.

The drivers already come with "coolbits", so you don't have to worry about that. Coolbits is actually not very special, even though people make it out to be. All it really is is a set of registry keys that enable the nVidia control panel's overclocking options and such.