Is there any reason that you couldn't set up a pond the same way you would set up a community tank?
Im in Portland, so probably another month before I would set it up, and would run a sponge and a heater. I would transition into an aquarium in the fall once it cools down, and it would stay there long term.
Im thinking Violet Cory's, Rummynose, Emerald Eye Ras, and some Apisto's