Transporter can import virtually all the stuff in a Poser scene -- including lights.

Once in C5Pro, you can adjust the Poser model textures. You can maintain a "connection" to the Poser object, so any changes made back in Poser will be updated automatically when re-opening the scene in C5Pro (watch out for tex. changes you made in C5Pro though -- they will go away if you do). You can also convert Poser objects to a mesh. I don't do much Poser manipulation in C5Pro, so others in this forum likely will have more accurate info on this than me.