One of these types of pump.
Some you ask like Rule, some like Johnson, some like other brands, pick your poison. I've been getting 5-6 years on average out of a Rule.
This 1600 gal pump is not crazy draw on your 12v circuit (my 17A Rule draws 20-25 amps
I am using the 17A for my deck hose only and the 1600 for the livewell.
Rule Tournament Series Bronze Base 1600 GPH Livewell Pump 209B | eBay
Splitting off thru hulls for multiple pumps is great for 1 less hole in the boat but you need to put shut off valves to all so you don't suck air.
If you drill for a nedwthru hull for the livewell only, obviously bronze, a seacock inside and a scoop down below.
If you run say Boston out to the east with the scoop & most open vein pumps you can shut the pump off and the scoop will pull the water in while steaming.
A typical washdown pump the pump needs top be running for water to pass through.
Also. Water in at bottom of your livewell tank and overflows near top keeps constant new water both keeping water temp down and fish scales, blood & other crap in the water will go out the overflows.