Thanks for your suggestions.
PluralEyes is a Mac program, running with FCP, and I have no use for either of them. Mine is a PC, and I use Avid MC.
The Horita TC generator is the one to go for. Cheap enough to buy two of them, or at least one for each camera.
And yes, my question is indirectly related to the new Tascam, but generic for the application I'm talking about.