Ralph, hi.
There are some posts related to your questions over on this other thread.
The Versus founder and CTO has a stellar reputation, Leslie Sherlin,
https://www.google.com/search?q=leslie+sherlin
Yes their headset has a “cross” shaped contact area with Cz in the center, C3 and C4 to either side, and Fz, Pz in front and back of Cz.
Take a close look at Pete Van Deusen’s Brain-Trainer system as mentioned in that other thread. You will learn a lot and be able to do your own assessments and select training protocols. Versus is much more automated and won’t do much to “train the trainer”.
Regards,
