Different slide (breachface is narrower), frame, firing pin, barrel, ejector, extractor, recoil spring, mainspring, magazine.
Springfield markets the EMP, it is scaled down.
9mm 1911s can tend to be very fussy as to ammo and mags-the pressure curve of 9mm is totally different than 45ACP as a result the timing of various portions of the operation cycle need to be addressed- feeding, chambering, extraction and ejection, not to mention barrel and magazine timing issues.
, no need for a ramped barrel- the round sits higher in the magazine and feeds almost straight into the chamber- the issue is the 9mm is too short for the 1911 platform, which was designed for longer cartridges similar to 45ACP, 10mm, 9x23 and 38 Super.
The frame has a different cut for the ramp- shallower than a 45ACP (not reversible without an insert or welding) though a ramp barrel cut can clean a 45 ramp out.
I'd suggest hand selecting your slide for correct breachface dimensions and location, this will save you a lot of headaches down the road, as will using an AFTEC extractor and the "Springfield" magazines made by Metalform- they have a spacer that helps a lot with feeding.