Quite a while back, I replaced the pump in our rig with a Shurflo 4048 pump and also installed a Shurflo Silencing Kit,
https://www.amazon.com/SHURFLO-94-59.../dp/B000WN5F96
This made a huge difference in reducing the noise from the pump. Actually, the pumps do not make that much noise, but the vibration in the plumbing while the pump is running is the majority of the noise. You need to make sure the pump is isolated from the hard PEX piping by installing the silencing kit, and to make sure vibration is not transferred to the plumbing, you might have to shorten the PEX going to and away from the pump so the flexible kit parts can really isolate the pump vibration.
I find, a little noise from the pump is good, so you know when it's running and also when it's not and you want it to be running.