What will be your cpu and cooler?
What will be your graphics card?
How much case fan cooling you need will be determined by your answers.
Case fans can be powered three ways.
- A molex connection(4 pins white end) is connected directly to the psu and always runs at full speed.
- A three pin connection which is voltage controlled. Speed can be managed by the motheboard.
- PWM(pulse width modulation) which has the 4 pins. It also connects to the motherboard.
Download and read, cover to cover your case and motherboard manuals.
You will find many answers, some of which you never thought of.
Almost certainly, the supplied fans can be connected either to the psu or to the motherboard.
The particular model includes a 120mm rear exhaust fan which you almost certainly should keep.
If your cooling airflow needs are modest, the single front 120mm intake may be all you need.
If you need maximum cooling, you could add 1 or 2 120mm fans to the front.
If you have more fans than you have fan headers on the motherboard, you will need to use a fan splitter that will handle two fans and use the same speed control on both.
Unless the fans are high rpm noisy versions, I prefer not to manage them at all.
If they run at 900 rpm, you will not hear them.
1200 rpm will have a steady drone which you may not want.