Styles for the busty woman can be found at Eris Apparel.
The site has clothing available for the difficult to fit average framed woman with a larger than average bust size. I can say that even as a former plus sized woman the selection of clothing that fit this area is slim pickings!
I find that when I buy a t-shirt (say mass superstore) it will ride up instead of the hem laying at my waist. So on the same line as maternity clothing, you buy the size you are now it will just fit you properly! The clothing available through erisapparel.com, while on the pricey side, was designed with an extra 4" added to the bust line. If you are a D cup or greater but still have regular S/M/L sizing everywhere else this is a site worth visiting. The selection is decent & they have a newsletter available giving tips & tricks on living with a busty figure.
If you feel you shouldn't have to have a breast reduction to have your clothes fit properly this website could be worth your time.