I found a big library of free celebrity faces for FaceGen, as .fg FaceGen files.
They’re from 2010 but I assume they’ll still work with FaceGen Artist Pro, software which lets you output famous or custom faces/heads for all Genesis generations in DAZ Studio. There’s a lengthy new tutorial webinar here, including things like work-arounds for neck-seams caused by the different body/head textures.
Carrara 8 is DAZ Studio's official 'big sister' software.
Carrara loads all DAZ and Poser characters and scenes,
and supports LuxRender for top-quality realistic rendering.