Im not a big fun of postgres clients like pgadmin, not sure why, but i always favoured psql over everything.
A friend of mine wrote an atom package that brings psql into atom. Which is awesome. It's tested in linux and (briefly) in osx. In osx i only had to change the path for psql because for some reason it didn't get it from the environment. Feel free to check it out and spam him with any issues you might have.
Link for the package can be found here.
Thanks for reading
-- Vasilis Ventirozos