For case fans go for 140mm fans that has the letters AF in them since that stands for AirFlow. Unless you have a very restrictive case when it comes to airflow like alot of panels, fine mesh dustfilters, etc etc, everything that will block your airflow in a way. If that is the case then go for static pressure fans.
For the radiator you will 95% of the time want to have fans that has the letters SP in them since that stands for Static Pressure.
When it comes to then noise part:
That comes down to what RPM you run the fans on and how mutch turbulence you generate in your case or radiator.
I always use alot more fans than I need to just to keep the system silent.
4 fans at 500 RPM you will not hear, but you might hear 2 fans...