First and foremost, if we are talking Ford Focus, we are talking the blacktop series of engines which means the cams are EXACTLY the same in both the 1.8 and the 2.0 so changing them will make no difference to performance whatsoever (and for the record, so is the throttle body, inlet and 99% of the cylinder head).

Piper cams would see some difference in performance yes, depending on which cam spec you go for. What is it you want exactly out of your focus?