wow.  after all that work i think you should take just a little bit more time on his renders. not because you've done an awful job, just because i think your model is so good but the renders don't show all of his detail.  so much is lost from your initial pics to these Poser renders.  i'm tempted to buy him just to try to work on his materials.  just in case it would be helpful for you to know, i would work with my tweaks to bagginsbill's VSS default skin shader and teeth shaders, my default white room setup which uses a flat white IBL and spotlights with bagginsbill's inverse square falloff shader, and if i were feeling really adventurous, try to make a mask to blend a skin shader with one of my hair shaders.