Ah allright, so I can use some really high airflow and static pressure fans for the better performance, and cheaper price, if I can tolerate the noise.
I was thinking about buying some Noctua Redux 12 1700RPM PWM fans, but they are quiet expensive for me right now.
So I was thinking about some Nanoxia Deep Silence 120 1800RPM fans as well as the Scythe Slip Stream SY1225SL12SH, which are pretty awesome considering both airflow and static pressure but are considered loud.
Also I can use a lot of fans I think, so if I buy some of the Nanoxia ones, and later I buy some Noctua, I can use both, so maybe I'll have a better cooling performance right?