It might be worth considering the Noctua NF-P12 PWM, probably as quiet or quieter than the other two fans you mention. Each Noctua NF-P12 PWM comes with a PWM Y cable, top speed limiting cable and extension cable which would enable you to fit them to your case without buying anything else. This fan is quieter in PWM mode than it is under voltage control. You can chain the fans off your motherboard CPU PWM fan header using the supplied Y cables. The chain will run at minimal speeds at idle and low loads, but will ramp up under gaming loads. If the speed limiter cable (LNA) is used the fans do not exceed around 900 rpm - barely detectable once in a case. Available from sources such as
this one.