"Gary RVRoamer" is right about the pressure myth. Most PEC lines can handle 85 to 100 psi. Go to Camping World's website and type in water pumps and read the specs. The good quality ones provide 55psi.
I bought a good quality Watts regulator with a pressure gage and set it at 55psi. There are certain things you can go cheap on when RVing, but using a cheap regulator should not be one of them, unless you're willing to suffer through low water pressure.
You can see how I mounted mine. (I later changed the hose clamps to PEC clamps). On my coach, the water hose and reel is rated to 150 psi, so mine is mounted at the coach.