HIiii, i have 380 unders which will gya an idea of size.
Im 5ft7″, 9st size 8. Was a 32aaa and now a 32f but dont look that,big!
I would go 410 if i was u, wish i could have went bigger but mr traynor wouldnt let meee as u will see i had no breast tissue. ,410 is only 0.3cm diameter more and 0.1 projection more than 280.
Def 410 xx