I need input for a baitwell pump

[Mikem8560]

m building a baitwell so i dont have to use the old floor on e in my 20sf. im about ready to install and will need a pump. Id like waterflow while the boat is moving and pump off.
the pump isee online like this

they seem they thread into a seacock but wouod this bee to tall above the waterline and would that matter priming if there was even room in the rear bildge to have a bronze scoop thrihull with a seacock then the pump?
has anyone done this on a 20 and how did you set it up ?