Randy that AquA Lifter should be perfectly fine for your need. I have been running my current one 24/7 as an ATO for almost 3 yrs now with not one issue (its run dry a few hundred times even).
Where is it leaking from?
A submersible pond pump from HD, Lowes or harbor Freight will work as well but you will need IMO a manual timer that goes by 15 minute increments as well as a ball valve to reduce flow since 2 gallons will move in a few moments as Im sure you know.