Here are some great designers that you'll find in post bridal stores for bridesmaids dresses as well as bridal gowns:
After Six: http://www.dessy.com/bridesmaid-dresses/aftersix/
Desy: http://www.dessy.com/
Alexia Designs: http://www.alexiadesigns.com/
Alfred Angelo: http://www.alfredangelo.com/index.aspx
Allure Bridal: http://www.allurebridals.com/
Bill Levkof: http://www.billlevkoff.com/
Bonny: http://www.bonny.com/
Davids Bridal: http://www.davidsbridal.com/
Forever Yours: http://www.foreverbridals.com/
Group USA: http://www.camillelavie.com/
Impression: http://www.impressionbridal.com/
Jasmine: http://www.jasminebridal.com/
Jordan: http://www.jordanfashions.com/
Maggie Sottero: http://www.maggiesottero.com/
Marys: http://www.marysbridal.com/
Mori Lee: http://www.morilee.com/Bridesmaids/
Raylia: http://www.rayliadesigns.com/
Venus: http://www.venusbridal.com/
Vera Wang: http://www.verawangonweddings.com/
Just a few tips:
1. It is my opinion that long bridesmaids dresses is more formal
2. Gathering, bunching, etc in the mid-section slenderizes
3. Straps are more conservative
4. The bridesmaids dresses don't have to be the same design, you could pick the color and then have the girls pick their own style that best fits their body shape (since they are buying them, then they might like them enough to wear them again)
5. Some people have the maid of honor (MOH) wear a different color to stand out, but you don't have to at all!
http://www.amazon.com/Strapless-Satin-Formal-Bridesmaid-Holiday/dp/B00144HXH4/ref=sr_1_1?ie=UTF8&s=apparel&qid=1282531948&sr=8-1