The bumper will be fint but for the headlights, you will need to change the wireing to fit facelift ST170 headlight to a pre-facelift Focus.
Fitting ST170 headlights is a popular mod, I did it on both of mine. I was lucky that I bought some looms that were already converted so it was just plug and play.
Go on the Focus related forums, FFOC & FocusOwners, you may have more luck. On FFOC, there is a how-to guide to make them yourself. Mine were made using VW Audi connectors which were perfect for the job.
Just to give you the idea, these were my 2 Focus's with ST170 headlights on.
You can also get clear lense's for the headlights to replace the orange. Just need to cut the back of the light open, replace & then use some sealant to seal it back together.
Andy