Well, this probably isn't the answer you expected... my apologies.
The only "real" way to find out what driver will work with your card/system is to ask someone with real experience with your specific card. Google didn't help me much with your card..
So lets go break your system shall we ;D
First we need to provide a failsafe in case we break your ability to run Unity. I usually just install Gnome Flashback so I can tinker with graphics drivers without using any of them.
sudo apt-get install gnome-session-flashback
You should then be able to log into "Gnome Flashback" from the login screen, but I recommend using "Gnome Flashback (No effects)" as it doesn't use Compiz at all.
Now we are ready to test your drivers. Go ahead and select one and apply it. I'd start with the tested and stable ones first.
Reboot and try logging into Unity and see if it works.. Try your games, make sure the graphics meet what you want. I recommend writing down which driver you tried and how it worked; it won't help to forget later ;)
If a certain driver doesn't work; log out of Unity (Or if you can't, press Ctrl+Alt+F1 login and run
sudo reboot) and log into "Gnome Flashback (No effects)" and remove the driver. You'll find additional drivers in the software center under
Edit -> Software Sources in the "Additional Drivers" tab.
Repeat, starting from step one until you get a driver that pleases you. If you don't find one.. well... I don't think there's anything you can do about it..
This is the method I use to find a good driver. It has always worked for me.