Trev,
In case you don't know some of these facts...I'll offer a few. I have this setup.
1. You'll need an adapter plate regardless. None mount directly. I have a Leaf plate built for a Valeo 11, but it will work with any 645AFD back. It required slight mods to fit a Phase back.
2. Different adapters are available for other mounts (Hasselblad and Contax, I think).
3. Phase backs require a wake-up cable. I used a cellphone headset with answer button, rather than pay through the nose for a real one. It worked on my H10, and should work with any H or P series back.
4. I don't think the ZD back has a wake up port, so it may not work on your camera. I read that it only works with the Phase adapter that only works on the IID.
5. Leaf backs do not require any sort of wakeup.
6. You'll need a focusing screen mask. I got mine from Yair (yaya) on this forum. He's a great resource.
7. My adapter seems to report an ISO800 to the camera, making the AE finder useless. Yair says this is an anomaly, and it should report 50 or 100. Not sure if the more expensive plates have ISO setting capability.
A good thread to read:
http://forum.getdpi.com/forum/showthread.php?t=9055