Here is the kit I was looking at:
OEM BMW E92/93 LCI Front M Sport Bumper Kit
It comes with: Front bumper, grills, airducts, engine shield, and misc. parts required for installation. The shop told me that all of these items would need to be swapped out to get the proper airflow, etc.
Personally, I'm surprised that so many parts change. Seems like a pain in the ass for BMW and certainly isn't as cost effective in mass production.