thanks a lot. I think I will stay with ek9 brakesI've been looking at this recently for another reason but the S2000 disc has a different offset to the EK9/EP3/ATR.
From what I can gather you can use the S2000 caliper/carriers but you would need ATR discs and space the carrier accordingly as stated above, or an EP3 disc and have the centre bore enlarged as it's too small for an EK9.