Celtic, yes, according to bra intervention I should be a 32C which does fit a lot better than the 34/36B I used to wear before measuring properly. I have tried on a few bras in a 30D as well but the band was ridiculously tight and the cups were too large / gaped massively at the top. I think it's probably more of a shape than size problem right now.
Dog, leedy, ruby, Challenged thank you, the Cleo bras sound really good! Will check out the Maddie, Koko and Juna and report back in a couple of days. The smaller cup sizes seem slightly more difficult to get hold of, so will have to either order from a few different sites or try them on in store.
I also ordered a Freya Deco bra earlier before reading that there are different ones. Just checked which one I bought - Deco Charm, yay!
leedy, the Mimi Holliday bras are gorgeous! Sadly I'm a bit fat right now so will hold out until I've managed to lose the weight and treat myself then.
Terra, thank you, I will keep Natori in mind for my next trip to the US!
Lots of great advice from the women of MN as always, thank you very much everyone!