What the title says really, I do a martial art where we wear breastplates. The sport (as with many martial arts) is male dominated, and even with as much alteration as reasonably possible, the breastplate doesn't really fit that well because of the size my boobs. Before trying a female breastplate (which I don't think will help anyway), I want to try a bra to flatten me down substantially.
So, recommendations for a very supportive sports bra to flatten 40Ds substantially please!