hey have you tried ATI's drivers for linux? ( after installing it on my suse 9.3 i was forced to reinstall the whole OS)
and second of all NVIDIA rocks... when it comes to linux ( well to everything:P)
and second of all Nvidia drivers are are easier to install and perform better!
i have a ATI 9200se on my linux mechine and i'm too scared to install ATI drivers because i know they will mess up everything!
i miss my GF 2 MX
Also most workstations which are used for rendering are running linux With nvidia QuatroFX cards!
and hey i never had problem with my nvidia cards on any linux distrs.!
Linux SLI - well there might be one... soon!
because you could make SLI btw QuatroFX cards so i think they are working on that, not sure though.
If they do that would be really cool :P