The quietest fan for the CPU, that gives you the volume of air to cool efficently, is the PANAFLO 46.9 CFM @ 3450 RPM. With freight they total $ 17.00 from NewEgg.
The same fan can be used as an auxillary intake for the front of the case.
The heatsink that provides the best cooling is the ALPHA PAL8045, but since you stated 'fan', I assume you don't need a heatsink. If you need a H'sink there are few better, and many worse than ALPHAs - but you MUST have ZIF mount holes on the Mobo to use it. What mobo are you using?
The PAL8045 is about $ 40 with shipping, there are several places that carry them. I only use ALPHAs, I don't trust ANY clip-on device to secure a heatsink to a CPU.
(They can crack the chip, or fall off and cause damage to either internal components, or if the system is turned on - kiss the CPU goodbye, burned down)
You can also use a PANAFLO 39.6 CFM @ 2950 RPM as an auxillary exhaust fan on the rear of the case. If case fan intake exceed the case fan exhaust volume, you end
up with a case overpressue which helps to keep dust out of your system, if you have a filter on the intake side.
First and goal from the one -
What do you do ?
Punt ! - The other team would never expect it !