Simplybe has some seriously cute swimwear. I just caught a 40% off deal there yesterday. I'm in a 16 (14 in some things), but my boobs are still massive. I ordered this Panache swimsuit because it comes in bra sizes. The straps come off and it looks adoreable, but I have a feeling I won't be able to wear it like that.
http://www.simplybe.com/all-swimwear.../invt/ro617el/
I also got this tankini. I know some women aren't comfortable wearing them, but I wore tankinis at my largest. I also like halters to hike the girls up in. Most bathing suits with the pads and shelf just don't work for me.
http://www.simplybe.com/bikinis+tank.../invt/ro393el/
If you worry about your thighs, they also have some really cute bathing suits with shorts. I have a tankini with shorts thay I adore for more active fun in the sun. I feel so sporty and cute in it. The shorts are just short enough to where I feel sexy, but just long enough to give me some coverage.
ETA: I almost bought that swimsuit, 586! I had another like it years ago and adored it! If I wasn't so tired of hiding myself in black, I would have gotten it.