I'll second or third Charley. I've ordered a few times on Aquabid from him and this week ordered right from him for some things I can't get locally or Aquabotanic.
Very nice guy and he does tell you when the stuff is coming in if he does not have it on hand and when you will get it. He just got another shipment in this week and he did have it on his list.
Other then Charley for harder to find stuff I have always been happy with the handful of orders from Aquabotanic.com. Robert is a great guy too. And his' CS is top notch. Never been let down there either. And Aquabotanic does have it listed on his site.
As for the other places, I have no experience with them