You can totally do both! Cory's are great with females since they really don't share the same level of the tank most of the time (except for my one female whom I've nicknamed Queen of the Depth and she shoals with the cories time to time lol) and with the shrimp, shrimp go all over so it's really not going to bother the cories either. And Amano's are big enough that the girls usually won't try to pick a fight although you may come across a few dead time to time.
I suggest cories over shrimp though just because they poop less and they get along fantastically with my girls! With all Betta's actually, I had a male in there once (before the girls) that totally didn't care about the cories