I'm no expert on this either, but I did a quick search for fish-friendly pumps. Looks like most of these designs are axial pumps, i.e., big, slow turning prop / screw type pumps. These are all low-head types of pumps. Likely more difficult to keep them alive if you have to pump them up a big hill. If I had to use a conventional centrifugal pump like a trash pump, etc., I'm guessing the largest diameter pump (i.e., 4" rather than 2") running at a fairly low speed would be the best bet. But i'm just guessing.
