Which CZ Lens for A99?

The 18-55mm on your NX200 is like a 28-82mm lens on an A99.
The 16-35mm lens at 35mm is like your 18-55mm at 24mm setting, which is good for group portraits and full body, but not a focal length you'll want to use for headshots etc. It will require you to get too close which means more perspective distortion, which isn't nice for portraits(unless you specifically want that).
You can take a "portrait" with any lens, but there is a reason that 85-135mm(on FF, 50-105mm on APS-C) range lenses are classically refereed to "portrait" lenses. The short telephoto length provides a slight amount of perspective compression that is very flattering.