I have a shure flow (I think a whisper king) in my trailer and I am very happy with it. I also have put in an pressure tank and it helped a lot with low pressure cycling of the pump. I would recommend either to anybody.
Test the pump before you install. Have one in my trailer which was noisy from new. Bought another one for another project and it was whisper quiet! If you get a noisey one exchange it!
I added the Shure Flow accumulator tank it worked some what for the low pressure cycling issue. Used material meant for quieting compressor motors under the pump, also wrapped a blanket of the material over the pump. Biggest noise reduction came from glueing some of the material to the inside walls of the cabinet where the pump is installed. That alone sucked up huge amounts of the sound.
Another thing to check is if there is a coil of hose off the pump. A couple coils of hose help reduce hammering noise. Helps reduce the hammering. Look to see where the water lines runb against spots on the trailer. Put pipe insulation on those parts. Hose hammering on the trailer makes huge noise too.