Pump Brand - Johnson, also sold under the label of 'Marpac'. Best pumps put there! My bro's combo washdown/livewell pump lasted 14-seasons of heavy use on a boat expressly used in saltwater.
I've also had good luck with Attwood pumps, but for anything heavy duty, I opt for the Johnson-branded ones.
A good source is https://www.surplusunlimited.com, as they sell both brands. Others may sell them too I'm sure.