Just thought I would let anyone know that was wondering that it is possible to use Rivatuner 2.0 15.8 with the 7900 series GPU's (no matter the drivers). This has worked for me, I dont see why it wont work for you.

Open RivaTuner

Tab to Power user

Rivatuner 2.0 RC 15.8 \\ System

ForceVGADeviceID (Set Value at 98)

This should close Rivatuner. The next time you open rivatuner you will be able to adjust fanspeed and adjust clock frequencies. I apologize if this has already been posted.