What flattering style of bridesmaids gown for plus size?

My aunt is getting married and she appointed me to handle all the fittings and etc. She included some of her plus sized friends and I'm having a terrible time picking out dresses that would flatter them because I couldn't see much, here in the internet. Oh, and my aunt is getting married this June. Links and tips will be very much appreciated. Oh, and please don't tell me to do the cover-up or shawl thing. It's going to be hot and I don't want them to feel uncomfortable.