Base figure gen8.
Base figure gen8.1 which daz themselves describes as an upgrade for facial features and facial expressions which comes free when you upgrade daz studio to the latest versions Victoria & Michael | Genesis 8.1 | Daz 3D
Same number of stomach sections, but the subsections have been doubled it seems. No idea if that would help you with deformations or not though.
Also, there’s the HD add-ons from daz3d, but I honestly have no idea what they might do as their description is so vague and confusingly over my head.