So many great suggestions--thank you all!
Kate, as you said, pricey, but might be worth it. There are a couple colors of the racerback tank that I really like.
Jenn, thanks for validating. I nearly didn't post, because I know many people here are bustier with smaller ribcages than mine.
Janet, I think you're right on the money about why companies have gone this route--more pieces=more money.
Sue, thanks for the link! Interesting that that shirt is called a yoga top. I usually think of those of being more form-fitting, so the waist stays on your waist, not your face, even in inversions. Apparently not!
LaPed, thanks for the suggestions. The ribbed one looks a little more fitted than what I was hoping for, but if the ribbing makes it easy to put on and off, that might be the one.
Sal, finding a fitted yoga top was hard? I raise you and say finding a non-fitted workout top is harder.
Angie, thanks to Sue's proof-of-concept link, I'll have a look.
Zaoebi, thanks for the link. Those look more padded/formed than I like. I appreciate you doing the legwork.
I'm off to investigate your suggestions