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 at 1000 - 1200 RPM
For Static Pressure fans you can look at:
https://www.ekwb.com/shop/radiators-fans/fans/120mm
http://www.bequiet.com/en/casefans/722
http://www.corsair.com/en-gb/ml120-pro-120mm-premium-magnetic-levitation-fan
http://www.corsair.com/en-gb/air-series-sp120-high-performance-edition-high-static-pressure-120mm-fan
http://noctua.at/en/nf-f12-pwm.html
https://mayhems.co.uk/fans/120mm-nidec-gentle-typhoon-performance-radiator-fan-2150rpm-68cfm-black-edition/
http://www.blacknoise.com/site/en/products/noiseblocker-it-fans/nb-eloop-series/120x120x25mm.php
As for AirFlow fans... There is a ton of them out there, just read some reviews and pick the ones you like.