It's relatively easy to get some images of the place from Google (some identical images appear to have been used by Nathanial to ID the location of his body).
Imagine something like this:
The layout of the building is on public record, although a recent update to the blueprints has been listed as "unavailable". The plan you get a hold of is around 2 years old (I've had a super busy day and haven't had time to finish putting this together...)
The organisation that runs the place? That's a bit of a nightmare. There's a known board of individuals, but the funds for the hospital are largely provided by a series of Venture Capital groups and other monetary funds. It's almost impossible to find out who actually has the controlling interest in the operation.
As far as individuals, Harcourt can only give you the names of those he knows to have been invited to inspect the place (he can't guarantee that there are others). They are General Ranulph Fairweather (Pentagon Hawk), Richard Moss, Brandon Rochester, Richard Heppelwhite, and Michael Schermer. The Four names on that list are all very wealthy men, known industrialists with huge ties to the arms industry, private security forces and a mass of other business interests. They're all on the list of the richest men in America and all donated to the sitting President's campaign fund. You can't find anything to link them to the hospital. There's very little else on public record that would mark them out any more than you'd expect from four wealthy white men.
Physical recon of the place confirms that it is more heavily guarded than you'd expect a standard hospital to be. The building is in the middle of reasonably large expanse of private land. To drive in you have to go through one security checkpoint (2 men) at an entrance gate, and then drive 400m to get to the hospital itself. The main door has another security checkpoint staffed by 2 guards, and a team of 4 men with dogs do routine sweeps of the building exterior and grounds during the day and night. The grounds are fenced off by a 8' spiked fence and there are regular security cameras. You'd guess, apart from security guards, there are around 20 staff (doctors and nurses) on any one shift.
At 10:30 every night a black van drives onto the grounds and disappears into a doored parking garage. It comes out at 06:30 every morning.