Photoshop from picture to Na'vi (Avatar)

Hello. I got a high resolution picture I want to turn into Na'vi Avatar face. I know it's not hard to do so useless to overprice it. I need this high resolution picture to still be high resolution when work is done. It has to be the more realistic possible, like in movies. I will print it as a poster, so only high quality image. /!\ PEOPLE WITH SIMILIAR PROJECT IN THE PAST WILL GET PRIORITY; PLEASE SEND SAMPLE OF WHAT YOU DO /!\