Bravissimo do good swimwear, it's designed for big boobs and so much better supported than usual swimwear. I'm usually a 36G (told you they were big!) but I found a size smaller - their 36F swim top was really flattering, it just held everything in place really well (but the size thing might be just me!)
First of all, avoid asking men for fashion advice, unless they're gay or work in fashion. They have NO clue. If they could dress women as they wanted, we'd all be naked. (or flashing lots of boob, bum and leg). If it is a floaty fabric, it doesn't look elephantine. It looks floaty, relaxed and feminine, and you will look gorgeous, especially holding a brand new baby.