At the risk of resurrecting an old thread, I'm going to add to this one anyway because I found a site that is totally worth adding.
If you're looking for something for elegant night, try zaftique.com. They had 12 pages of great dresses with 99 dresses per page. I've got two dresses on the way so I'll have to update you all on how they do, but they have sizes up through 6x (or on their site, 6z). The prices were fairly reasonable for semi-formal wear. Their tops are just to die for, but they are spendy for sure.
But yeah, I feel ya on trying to find something to wear and I'm really frustrated with clicking on something only to find out it's out of stock.
I keep saying I really need to open a plus sized store in my fairly small town..we have nothing here but CJ banks and they're just not my style AND they don't go high enough for many people.
Because you know, we all used to skinny dip, but now some of us have to chunky dunk