I am admittedly a newbie to HVLP...

I have read that a viscosity cup is useful (if not necessary) in order
to select the right nozzle size and to know how much to thin the liquid
being sprayed.

Googling I saw Ford and Zahn viscosity cups of various sizes... which
left me confused about what type of cup I would want for "run of the
mill" HVLP spraying where I might want to spray anything from shellac to
lacquer to poly (oil or water) to latex paint...

Could someone point me in the direction of what cup (or cups) I might
want to get for such purpose?

Also any recommendations for specific cups or brands?

Thanks!