It all depends on when they get the stuff from Hasbro.
Orders get postponed from almost every on-line shop, SWShop is no different. For example, the Lucas Collector packs originally said they would ship April 20th, but they didn't actually get them and ship them until May.
So, even though it says "Sep 1st" at SWShop, I wouldn't hold my breath that you will get it then as they have been known to be late from time to time.
As for the second part, the "fast delivery" depends totally on when you place your order. Once it ships, they usually ship FedEx, so the closer you are to California, the sooner you will get your stuff.