Need to know what is the quietest & highest GPH return pump

[Mrfish55]

I had the same problem as you, was getting nasty resonance and driving me crazy, I installed rubber couplings on the intake and returns right where they enter/exit the pump and installed damping pads ( from Sears, intended to go under washing machines) and it made a huge difference to the sound I was having. Changing out your intake to a larger line should make a big difference for you as well, restricting the intake can cause cavitation and vibrations.