Suz,
Congratulations! What an honor! You mentioned that you could order from J Crew. They have some beautiful dresses in their wedding collection that could easily fit the bill. I'm partial to the navy silk chiffon. I just checked and they have long and short dresses in navy. My daughter had her bride's maids wear J Crew dresses and all of them said that they either wore the dresses or plan to wear them again. They are very "unbride's maidish" if you know what I mean!