yes we can of course use Arca Plates too. What the HCam-B1v actually is: there is a 120x120mm size hole on the front. onto this we can mount any original plate holders,
in case someone wants this recessed, we can also do this. Every HCam is custom built and made exactly like the customer needs it. e.g. there are small things that make life easier:
we use the same battery mount for the camera as you back has, so you only need one charger for both !
For shooting out of Hand, I would not recommend this, for some simple reasons:
if you want to use an 80 Mpix back with reliable sharpness (for each shot- I´m not speaking of the lucky one out of ten when taking a deep breath and leaning on to something)
you will need something like a 1/500 sec, when you go tele (longer than twice the image diagonal size) that should be 1/1000 sec.
Now with a standard base ISO of 35 (for best image results) to get these timings with lets say f8 you will need "A LOT" of light......... so I´d say forget it.
What you will need is something like a D800E with a stabilized lens and maybe 400-800 ISO and then you can use this for a shot out of a heli.
As long as there is no comparable CMOS and image stabilization for MF just forget it.
Greetings from Germany