Unfortunately I probably won't be much help, but do have some awesome suggestions. I know you said preferrably from EF, but I just don't find lingerie here that is unique enough for me to pay the price and a lot of it looks so ill fitting
Also, I'm not a big-boobed girl anymore. Lol. I had some boobs several yrs ago, but not much anymore. I love to collect really sexy, unique lingerie so it's taken me quite some years to find a good place to buy. I would suggest CorsetChick.com if you're looking for a corset that's hard to find or if you have a hard time finding your size here they usually have it. They're not all corsets though. They have some outstanding clubwear dresses and some of the most beautiful lingerie I've ever seen. (Can you tell theyre my fav? lol) Anyways, I'd recommend them. I love lingerie, but I'm also a super cheapie & honestly it's really hard to find lingerie that isn't outrageously high. CorsetChick is so cheap! Most of their corsets are only from $20-27 and that's unusual. They also have plus sizes too. Anyways, they have great fitting lingerie and a size chart for every item so you can be sure. I know it's not EF, but it's worth a try.
FeelingUSA.com is a pretty good site too for what you're looking for, but not as cheap as Corset Chick. I just ordered 2 sets of lingerie from them. I ordered a pink corset that comes with the black tu-tu skirt and a leopord corset that also comes with its own black tu-tu skirt and I've seen the same exact corset on other sites for over $65 and they were only $27 each! That's a great price and very hard to find.