Blast it, but I really appreciate you checking. I'm assuming most of my top issues stem from the fact that I'm a DD. Unfortunately I'm beginning to think I'm doomed.
A karate style gi jacket CAN be altered to fit if you have somebody local to work with you. You want it to fit properly across your full bust/around upper and mid back as the alterations will be to remove excess fabric at neck, shoulder and upper chest plus diminish any excess fullness at the waist.