Depending on the size, I generally use from 16-24 sides and in Poser it renders pretty smooth.  Turning Smoothing on in Blender will give you a fair idea how it will look in Poser.  You could always make a few test cylinders at about the size you want with 12, 16, 20, 24, 28 and 32 sides to see how they look.  Just make them, line them up in a row, export as a single obj file and import into Poser.  Hit render and see what you have.