I'm off to meet a friend at Kleinfeld. She's getting married on September 5th and nervous that if she doesn't make a decision soon she won't be able to get the dress that she wants.
It's important that you order your wedding dress at least 6 months before the wedding to ensure that the designer has enough time to manufacture it and there's plenty of time for alterations - you'll probably have three alteration appointments.
But just because you hit the 6-month mark doesn't mean you should settle for a dress that you don't love. There's always the possibility that the salon can rush the dress - though you will incur rush charges.
I honestly believe that when you try on the right dress you'll just know that it's the one. Don't buy a dress that you don't love because you're worried about the delivery schedule. I'm sure the salon and designer will work with you to get your dress in on time even if it's less than 6 months to your wedding.