Mine has a vacuum pump as well, mounted up front. The car's plumbed and wired so it
can be mounted in the engine bay, but there's really not enough room there. I'm not
sure just which pump they used, but it might have been
this one.
I came up with a whole list of possibilities at one point (a GM part #, a Ford part #
from an F350 diesel truck, ...) but I can't find it now...