Here's a great tip: just adding a simple satin ribbon to a gown you'll buy in a regular wedding store or a bargain store will do the trick! Also, you can find some lace and arrange it in a nice rose pattern, as shown on the third gown.
Look for a good bargain wedding gown and rework it with a nice detail, I mean, why not learn from the best out there? ... and by far, Vera Wang is one of the best wedding gown desighers.