If you would like to try a fitted dress, I think it would be wise to try a wrap dress or a sheath with strategically placed color blocking.
A wrap dress would conceal a bit of tummy and still be flattering for your bust. I think one with a sarong-style skirt would also be great, as it would balance out your top-heaviness.
Maggy London Leaf Print Jersey Wrap Dress | Nordstrom
A colorblock sheath could do wonders for your body, like this Stella McCartney dress made famous by Kate Winslet:
Stella McCartney Contoured Colorblock Sheath Dress - Bergdorf Goodman
The color blocking, like above, should follow the curve of your body OR band at the waist to really draw the eye in waist and balance out your figure:
Maggy London Colorblock Scuba Sheath Dress | Nordstrom
Suzi Chin for Maggy Boutique Contrast Print Jersey Sheath Dress | Nordstrom
Fashion Star - Sleeveless Dress by Orly Shani - Saks.com
T Tahari Dress, Geraldine Sleeveless Sweetheart Colorblocked Sheath - Womens Dresses - Macy's
Jones New York Dress, Cap-Sleeve Colorblocked Sheath - Womens Dresses - Macy's