First Post: Utility Pump Question

I plan to drain my pool for painting later this year and need a pump to keep ground water suctioned away. I have a PVC conduit under my diving board that leads to a sump installed under the deep end of the pool for this purpose. I've been advised that the pump needs to be ran 24 hrs per day, even if it's not pumping water, so the pump I'm seeking needs to be able to run dry and self prime when needed. I will be home for the duration of this project, but I want to be able to sleep comfortably knowing my pool will not float, lol.

If I have a hydrostatic plug, when the pool is completely drained, I will remove that and possibly give the pump a rest during my waking hours, so, there's that.

The pump needs to run on electricity and be safely operated from a 50' extension cord. The pump will sit on the pool deck and it's intake hose will connect to the pipe under my diving board or will be snaked through the pipe under my diving board as far as I can get it.

This project is on a fiberglass pool that has an 18,000 gallon capacity.

Anyone, please advise what kind of pump I need to buy.

Thanks in advance and thanks for letting me into the forum!!