Measuring according to the MN way, gives a starting point which is really helpful for those who have been measured at M&S, La Senza etc.
Bravissimo is the best place to go but there aren't that many branches. For example, I live in the SW and the nearest to me is Reading, a three hour drive away.
Fattyfattyyumyum It is supposed to be pulled tight, so try a 32F/E and a 34DD/E. I suspect that 32F will be the better fit in most brands. If you put your 34 on back to front, how far away from your body can you pull the band? Wearing it the right way round, if you scoop, is there overspill?
For context, I used to wear a 34DD, I am actually a 30GG.