Most established artists will not allow you to take pictures or take a copy of the artwork, others will charge a deposit to allow you to take a copy home.
Understand it is art and it's their concept. There are a lot of people out there who will come to you and get you to draw them up a custom piece with the intention of taking it to any old scratcher to get it done for pennies on the dollar.
Plastic surgery and tattoos, two things where bargain shopping can bite you in the butt in a very big way!
Jeff, take a look here
www.mikeparsonsink.com
Mike is considered to be the best of the best in the "skinaquarium". If you are not totally happy with your artists interpretation (never settle for less than perfect), show him Mike's website as a reference if you like it. Granted he can't copy Mike's work but he can maybe integrate some of his ideas in.