4 pin and 3 pin are interchangeable. 4 pin are PWM fans. They are usually used for CPU coolers. But its expected newer motherboards will have PWM fan headers for case fans too down the track.
Noctua if you don't mind the colour. Else, Corsair.
Will Noctua NF-F12 fans work in the Cosmos case? I thought I read that Noctua fans were four pin versus the three pin fan wire connectors within the Cosmos case. Your response would be greatly appreciated as I want to use Noctua fans in the Cosmos II case I am going to buy very soon. Thank you.
4 pin and 3 pin are interchangeable. 4 pin are PWM fans. They are usually used for CPU coolers. But its expected newer motherboards will have PWM fan headers for case fans too down the track.