It has been my experience that most Indonesian/pacific rim coffees are low in acid. Examples would be Sumatra, Sulawesi, Java, Flores, Timore-leste, Papua New Guinea. I'd also have to mention coffees from India as well.
We have a few pounds of Hawaiian Queen Kona. And when we make our yearly trip to Maui we bring back some Kauai coffee from a local store that gets each day freshly roasted. Its, the medium-roasted Estate Reserve is really good in both their Decaf and the Estate Reserve Peaberry and really low in acidic. But this stuff from those islands isn't cheap. .
The big bummer, you go there and spend a few weeks and drink nothing but Kona or Kauai and then come back to the states, its a big withdrawal. We found a lot has to do with the fresh spring water there at our place vs the filtered water here in our Fla home.