i couldnt find anone who knew how to bypass the internal pats system in a mk6 rs2000 ecu so id be quite surprised if you can do it with a much newer car like the focus im afriad mate. but you never know, someone may know how!
cant see why you rcouldnt use a basic system like magasquirt and just have the standard rs focus map loaded onto it though, wouldnt cost you even half 1600 id imagine?