Probably the rotor would work. Also, the B8 RS5 wave rotors work too (fronts only, rears are a different brake hub). The Ceramic/Carbon rotors are expensive and usually need to be paired with the correct brake pads (also expensive). Need to double check that the front Calipers are the same with the Ceramic brake option (rotors were increased from 365mm to 380mm), they may be different. There was a kit from Europe for Ceramics for the front of the C5 RS5 using all OEM Audi components but it was over $10k.
Edit: Just found the R8/RS5 Ceramic rotors for just over $5k a piece. I'll stick to metal rotors I think.