Quote - A request like this comes around every 3 months or so.

Viilters is correct, these requests come up often and are met with quite a bit of skepticism and suspicion.  There individuals willing, especially for money, but fear legal hassles if proper documentations and permissions are not present.  

If the OP intends to proceed, then written permissions should be obtained first.  Next, ordinary photos are not the best source to duplicate facial features.  Common camera lenses can distort to a degree.  In addition, facial expressions can influence the final outcome of base features.  Better to have a professional photographer take frontal and profile shots for starting reference point.  

However, Basicwiz is correct, the last 10% of reproduction is highly dependent on matching textures.