Just to update this thread… Convergent Design confirms that the Nanoflash is indeed an 8-bit recorder. But, a very good one. The two extra bits on the EX1 and EX3 are not missed much in that they are noisy anyway.
They recommended that the best B camera for an F3 is another F3 just as you recommended. But, if I were to use the FS-100, to not use the S-Log on the F3 so the two cameras could be matched to each other better. They too thought than other than another F3, the FS100 would be the best other match as a B camera and that the nanoflash was the perfect recorder for it. Again, not running the FS100 very flat to require a lot of adjustment in post.
They commended your recommendations. And, I love your lens choices.
Rk