I use the Johnson pumps with the built in solid state sensor.
I find mechanical float switches are OK on yachts and pacific 22s
But on something like your scorpion, a revenger - high performance stuff that "gets on top" rather than "goes through", the mechanical float valves hammer themselves into instant death - so the Johnson set up is nice being completely solid state. It's also a nice and compact setup for the stated flow capacity.
It's also a packaged setup - which I built a little stainless bracket (I ditched the included plasic bracket you can see in the 2nd pic) for so I didn't need to drill any holes in the pad (it's balsa and I wanted no holes in it) - just a couple of holes in the transom. Still not ideal, but rather that with some goop than into the balsa.
Not exactly what you are asking, but hopefully useful.