Hi Faye, I’m a 34B too and having 400 overs tomorrow,, I’ll let you know how I get on.
I think you were advised about drooping as it’s inevitable, my surgeon said the same but I don’t think it’s something to worry about. ( not yet anyway )
I originally chose 350cc and to be honest there is so little in it that it’s not worth taking up the offer of 400cc, barely a third of a cup size.
Try rice sizes at home with a bra on, I did and that’s how I made my final decision ?
Best of luck with whatever you decide xx