Pans and Little Giants are prone to noise issues.
Iwaki's are quieter, perhaps one of the quietest out there for their capacity. You can save money by getting an American motored Iwaki, either one is going to be nice and quiet. At the moment I am sitting about 12 feet away from a 55RLT running on my FOWLR and I can't hear it above the fans in the canopy.
You can also make the PW run quietER by placing it on a piece of foam building insulation, and using a short section of spa-flex in the plumbing to and from the pump (if you use hard plumbing. If you use vinyl tubing, it's moot), as sort of an "expansion joint" and vibration isolator.