The EC-7s in 18x9.5" ET22 and 18x10" ET25 will clear the Brembo 6 piston 380mm BBK and the Stoptech 6 piston 380mm BBK up front on an e9x M3, along with the AP Racing 368mm BBK and Brembo 365mm BBK. These same wheels will also clear the 380mm rear BBKs from Stoptech and Brembo also.
The ARC-8s in 18x9.5" ET22 and 18x10" ET25 will clear the Brembo 6 piston 365mm BBK, but not the 380mm version for the fronts. The 18x10.5" ET27 ARC-8s & EC-7s as well as the 18x11" ET25 EC-7s will work in the rear with a 380mm Brembo or Stoptech BBK.
Volk Racing TE37s in 18x9.5" ET22 also clears the Stoptech and Brembo 6 piston 380mm BBK in front of an e9x M3:
We will try to get brake templates for the PFC and Alcon kits to test against both the EC-7s and ARC-8s as well, but usually Brembo utilizes the largest calipers in our experience, so wheels that clear the Brembo 380mm BBK should clear the others as well with the same or smaller rotor sizes.