Where do pilot's get their POH's from?
What other material is normally available that provides info on an
aircraft besides the POH?

I'm not a pilot (yet) but would like to get my hands on a POH for a
Bombardier Global Express (BD-700) and Cirrus SR22 so that I can model
them in a scientifically oriented flight simulator.

I'm interested in the aircraft's physical dimensions and shape, the
systems and how they operate (electrical, hydraulic, pneumatic, etc),
the cockpit layout as well as the aircraft performance specs.
Is this all normally in a POH or are their other documents as well?

Who must I ask and what must I ask for?
Oh, and how much does this sort of info normally cost?

Thanks
Paul