Avionker, not unreasonably the US is unwilling to disclose much information about the 'special equipment' needed for Air Force One's mission even to the airframe OEM.
And what information would the OEM require? They certainly wouldn't need to know any specifics. Perhaps the approximate weight of components when approving structural changes, for example equipment racks installation, antenna mounting provisions, countermeasure mounting etc. Electrically , all the OEM needs to know is power draw on each bus, and perhaps provisions for load shedding. Also the aircraft are on the military register I believe, so the FAA type approval is not an issue is it?
As I understand it the main problem with the the VH-71 was the continuous moving of the goal posts, adding more and more to the requirement.