As with all of the CS products, there is a lot of overlap and cross compatibility. You can obviously do this in either flash or illustrator, but the primary question is when you are done with it, what is your next step?
I recommend The Wedding, Portraiture and Group Photography Guide to everyone who wants to improve their photography across these three areas. I have learned so much about this business and how to respond accordingly to customer requests which before I would have rejected. Thanks Bobby for writing such a great learning tool!"