On saturday, anytime will work for me. I have two JRock costumes that day.
How about 14:00 saturday?
In terms of organizing, I'm the one organizing this. It will not be a professional photoshoot, because I don't have the money to shell out for that, but I will definately alter the photographers that I know to our presence.
If you want a professional photoshoot, there are plenty of people around the convention who would be willing to do it for you, I'm sure.