So, I hope this helps. As I said, the lighting is extremely simple: I took an UberEnvironment2 (this light shader comes with every version of DS since 3Advanced; I think Poser has environment lights like that, too), applied a HDR image-based lighting map to it (the Park one that comes with DS), then I created one distant light, set it to specular only and positioned it so that it would come from the same place as the sun in the IBL map (this could be tedious, but I create a new camera at the coordinate origin, point it to the sun and then copy the rotations to the distant light, then up one rotation, usually X, by 180 degrees so that it looks the other way, not up into the sky but down).

There are other HDR maps out there - I like these free ones: [link] - these are panoramas, so I'm not sure if Poser handles them well, but I saw some nice free HDR maps specifically for Poser at Cath's site mec4d.com.

In DS, just using one IBL+AO environment light eats up all the specularity, so you definitely need that specular-only light; but I'm not sure about how specularity is handled in Poser (I have Poser Debut but the interface looks very confusing to me unfortunately).

To bring out the detail in displacement, I upped the UE settings to somewhat extreme numbers: AO samples 192 and max error 0.4; can't recall the exact AO shading rate at the moment, but it's 4, I think.