however, the RS bumper is
1) not out yet
2) still in prototype...knowing ford they may never release but there is actually a good chance of releasing this one (if that makes any sense)
3) IT WON'T FIT without serious body work...the bumber is designed to fit wide wheel arches...so if you put it straight on your Fiesta, you would have a massive overhang on each end!
4) The ST 150 will be coming out with a similar front, but again i think the arches on that are too wide, so may not fit standard model.