This is a Superfly render with all the texturing converted to Cycles and PrincipledBsdf.  Background HDRI, 3k, no additional lighting other than the ambient settings from the HDRI.  Fresnel was added to all the material zones.  The model is V3.  This is WIP and testing to find the right balance of the environment and textures.  

The background is soft because it is only 3K, higher resolution will give you a sharper image.  Also, I read that true HDRIs are already in a linear workflow so introducing them to Poser will require setting them to a Gamma correction of 1, not 2.2 like other image formats.