Without digging deep, I would have to say the the Brand MSI is more knowned than the Zotac. Now, being said that and seeing as to how you have posted this on the "Gaming
" forum, I am going to have to say that, even though you will be able to play some of the latest games, you won't get to do so on High or even Med resolutions and settings.
Why don't you give us a little more info on what you are trying to accomplish? We might be able to guide you a bit better w/o braking the piggy bank
WAIT A MINUTE? I just went to check your specs and see that you also have a 9800GX2. So... am I assume you are just looking for a PhysX card?