Shirts for those with a bigger bust

[TinyTRex]

Hi all,

Since Bravissimo no longer do clothes - gutted - does anyone have recommendations for where I can buy shirts that won't gape as I am a bigger busted lady?

Might not be what you're looking for, and my chest is a mere 38 inches, but I recently bought a work shirt from M&S and it had an extra little button at the top that you could do up to prevent gaping. I've since worn it a lot.