We use bully sticks from chewy.com. Our boys love em! I've read on here that some people don't like bully sticks because they may break their pup's teeth.
Here's the ones we get:
Bully Sticks 12" Dog Treat, 1 count
and
Braided Bully Sticks 12" Dog Treat, 1 count
When the stick gets to a nub, we throw it away and like Ann said, "Can't really say what chews will predictably be "acceptable" for her tummy, since every dog is different."