How much do you think that a map-sensor plus a custom re-map on a rolling road will cost?
You also need modifications to the wiring loom and some valve to control the boost,
which is probably not possible with the standard EEC-IV or run low boost mechanically controlled.
Are you sure your standard fuel pump is up for the job? Do you have an intercooler?
You should have thought about the money before you started this project.

Maybe, Maybe you could use the system from a Fiesta RS Turbo.