To answer the piston size question, this is direct from RB website:
"Pistons: Caliper pistons are 40mm and 44mm diameter (two of each). Pistons are made of stainless steel instead of aluminum commonly used by other caliper mfgrs which can substantially reduce the heat transfer (approx 1/10 of aluminum) from the pad to brake fluid. Pistons are vented to further reduce the heat contact area and improve air circulation thereby reducing more heat transfer."
I didn't get it all put on today but here are some photos to bring you guys up to speed. So far these are going together great!