I've been tearing my hair out ever since I read Hard Travelling Heroes (the tpb) because I have no idea who Neal Adams used as inspiration for Hal Jordan, Oliver Queen and Dinah Lance. I would love to find out if they were actors or famous people in general. Please stop my hair pulling.
I think Neal is just gifted enough to capture liknesses that appear to be from someone famous! Seriously, I'm not sure if he did use anybody for referance (unlike Alex Ross and others) but he does have a website you can check out and ask him yourself!