When I was a FTO, I had several female trainees grapple with this issue. Two of them were rather busty(one naturally and the other...not so much). The less endowed females just wore male patterned soft body armor. The two more endowed officers wore female patterned soft armor, such as this: http://www.safariland.com/BodyArmor/...ody-Armor.aspx
I can't claim to be an expert in these matters but I recall an eyebrow lifting lunch, where these two busty officers traded experiences and insight, while I did my best to mind my own business. The two definately agreed that finding the right bra was very important for managing conform levels under the soft armor. Neither liked sports bra because of breathe ability issues. The naturally busty officer said that a push up bra was critical to make sure she fit it the right spot in the contour of the female style soft armor. The officer with implants said she had better luck with some sort of adhesive cups that are designed for support while wearing strapless dresses.
It was an eye opening conversation but all in all, I was happier when the topic moved to fitting ankle holsters.