Brides Maid Dresses...

So ... I am going to be the maid of honor for my friend Liz's Wedding. She is getting married in Aug. 09. I am really excited, but not so good at picking dresses. I thought I would do some research to help her out with her decisions for us girls. I think that she once said she would like us to be in formal dresses (this means they have to be long) and I think she said the colour is going to be lavender, or lilac or something like that.
I did my best to pick out some possibilities that might look good on all the girls regardless of body type.

I tried to find the one on top here in a lilac colour but had no luck... It seems like a decent dress and it could be fun. The ones just below is really nice too. I think its going to be difficult to chose one. What do you guys think?