Sorry don't know about the b/fing issue, but will just tell you that it's normal to have up to a size difference in your breasts (usually the side you write with apparently).
Any larger than that and they can cause issues. If you have troubles with back pain etc talk to your doctor. It can also be fluid retention - they have pills for that.
(I myself have a 1yo pair of same sized girlies thanks to the lovely surgeons at chch hospital due to my greater than normal size difference causing major issues so I know how you feel!)
Oh and trust me most people don't notice. Not until I told most of my friends what i was having done did they even look twice - padded bras help a lot if you're conscious about it, but honestly most people don't care (took my DH a good couple of months to notice lol and he had a lot of time to analyse them

)