Figleaves- you can access it via debenhams online or direct. They have a massive collection of pretty bras.
M&S- are currently bringing out better bras too- speak to one of their bra fitting ladies for more details.
Bravissimo- make feminine bras for larger sizes- I don't own any but friends say they are good!
There are loads of lovely bras about these days for us bigger fronted ladies. Freya, Panache and Fantasie have some lovely ones and Ultimo have not long launched a whole new 32D+ range. As previously mentioned, you should also have a look at www.figleaves.com