I’m 5ft 4″, size 8 and 8 stone. Currently a 32B after breastfeeding and will be having 375cc unders on Thursday. I made it clear I wanted my new boobs to look and feel natural and everyone seems to agree that my surgeon, Mr Kazzazi is very good at achieving this. So, all that said, I’d say with your stats, 340cc would not be too big xx