It’s funny but your question is actually kind of hard to answer because there is no standard sizing among stores and brands.
I’m a 34C in most everything, but I’m one of those weird people for whom the +4 formula works and so most everything fits me. On the other hand, I know some women who take a different size in every. single. bra. brand.
Personally, AP bras are a bit snug on me; I find they don’t have a lot of give. AP also uses UK sizing which tends to run a bit tighter than US sizing. Ditto for their knickers.
On the plus side, I have found that AP has a really great return policy. So, since you’re not able to visit one of their stores, you may want to get a couple of bras in the size you think you are, and then after that, you’ll know which one works best for you.
Hope this helps,