http://www.figleaves.com/uk/home.asp
You can get up to a 46 J here. I bought a whole bunch and returned them all cause they didn't work. It was very easy to buy and return though, I would totally recommend it.
I was measured by Lane Bryant, Nordstroms and Macy's - They ALL told me I was a 38 DDD. However,the bras never LOOKED like they fit. I then went to a plus size boutique and tried on some larger bras and it turns out I'm a 42 H! I LOVE my new bras and they support and fit well!
Sooo, I guess what I'm trying to say is- I never would have thought that I was a 42 H, but then I tried one on and saw how much better it fit - perhaps these sites that are telling you these strange numbers are *at least* telling you that your current sizes may be wrong. But, then again, I haven't tried them, so they could just be wrong

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