A Formal Choice sells LDS temple-ready modest wedding dresses. They have dresses in stock and dresses that can be ordered.
Go to www.AFormalChoice.com, and click on "Modest Bridals".
Totally Modest has a huge selection of LDS modest wedding dresses. You can view large pictures and order conveniently online.
Just go to www.TotallyModest.com, and click on "Gowns".