Case and radiator fans

[Extasis]

Hi, I'm going to build a water cooled system and i want it to be as quiet as possible. But to a low price... I've looked at the Corsair Air Series SP120 HP (and noctua)and i know that they are good but are they really that good for the price. I'm looking to install 12 of them if no one says otherwise. I'm thinking of installing one 360rad and one 240 rad with push pull. I'm only looking for the cheapest and the most quiet fans (120mm only)

 

[Extasis]

And, does push-pull really improve the cooling on radiators? Or is it unnecessary?