Are you going to bring them all with you and let them choose?
I was thinking of going to a store and finding about 4 dresses and then let them choose from those 4. I would ideally like to find a dress in the same color in different styles. I love the look with everyone in a different dress just the same color. Plus all of my girls vary soo much in size!!! They are a size 4 to a size 18. Plus I have 2 bridesmaids preggo right now so when we go shopping in December they may not have lost all of their baby weight yet.