Direct fit the LBZ/LMM style pump is an upgrade due to left handed thread on the shaft. If you're willing to do some clearance on the pump you can run the LML pump/pickup tube and gain some additional volume.
As for oil the oil cooler, you can run the 17-19 cooler and continue to use the same oil filters you have now or you can run the 2020 cooler with the 2020 filter. To run the 2020 you will need the cooler, elbow, and gasket from GM. With the 2020 cooler you will also have to trim a heat shield tab on the manifold if running factory manifolds. I cannot confirm on aftermarket manifolds and the 2020 cooler. The 01-16 cooler has 10 plates, 17-19 has 14 plates, and 2020 has 20 plates.
The pump needs to be machined to clear the front cover or you can run the LML cover/hub and space your accessories out. I believe KidTurbo machined his pumps on the boat built and that is also the route I am taking on my pump.