Although recreating a 3D facial model from photographs is time consuming and exhaustive, it is very achievable  in Poser.  You need all your morph packs installed if you decide to spin dials.  Or familiarity with a good modelling program to create the necessary morph targets.  I have come to the conclusion that facial expression and mannerism is just as, or even more, important as the features alone.  They convey a better personal characteristic than a straight rendered look-alike.