Dan, StevR: I do of course agree with you. In fact, upon perusing this thread and thinking about it more, I have gone ahead and arranged to acquire a Nikon D100 back. It is supposed to arrive Monday. I can use it fully manually with my existing lenses and external metering, and it will be a good tool to use for projects like this, or indeed any project where previewing the lighting before using up precious film is important.
I didn't really want to burn anyone at the stake, especially as I would now have to include myself. The final pics I will shoot on Portra 160 or 400, depending on how the lighting works out.