In addition to the H3DII-39, which would offer tremendous capability in conjunction with the HC-D 28mm lens, as well as practical functionality on a view camera / technical camera, Hasselblad's CF (or CFII) Series back could be another consideration.
The new H2F, in conjunction with the current CF-Series or CFII-Series backs will allow you to use and properly correct the HC-D 28mm. The CF or CFII backs also give you portable, on-board battery operation when the back is mounted on any camera, including view camera / technical camera. On-board battery capability is not possible with the H3DII back, which is why you would need either the ImageBank II (with L-type battery) or bus-power via FireWire (ie. tethered). The H2F / CFII combination would give capability with the HC-D 28mm lens, as well as more elegant portable capability with cameras such as the ALPA 12 series, or the various digital specific view cameras (ie. ARCA-SWISS, Linhof, Plaubel, etc.).
As with all systems, there will always be some comprise for certain capabilities, which is exactly why the H3DII-39 would be ideal in conjunction with various HC-Series lenses, and "not as ideal" when used in the field with a view camera / technical camera. On the flip side, the H2F / CFII combination will not provide all same capability, image quality, functionality, and control as the H3DII-39, yet will be "ideal" when using the back on various camera platforms such a view camera or technical, super-wide camera.
I would certainly look at the various options out there, and investigate them all in detail. As you can tell by this thread, there are numerous options, all of which have merit, and capability depending on your specific needs. A qualified dealer should be able to help you narrow you options down, and go into the various systems and configurations in detail.
Feel free to contact me directly if I can be of help in your decision making process.