Many thanks for all the info guppy, much appreciated. The 182 we are using was actually a sensor platform for a law enforcement agency in its previous life, so it has all the appropriate holes already drilled in the fuselage. (Hard to keep it dry sometimes, but that's life I guess.)
The Paravision unit with the vibration-tunable isolation collar may be just what we're looking for, with some minor mods to house our cinecam, I'll be talking to them next week.
You seem very knowledgeable about the subject, any other thoughts you can impart regarding aerial filming?