Instead of changing fans did you try extractor ? I'm using 200mm one with a 3D printed adapter and it works really great, instead of 4 small fans doing crazy noise you're sitting with 30db
I guess this is only beneficial for those who want to get rid of noise only, also I will like it if you can share a picture on here just for a glance you know? Maybe it can be useful for another project or for some people on here..
You can always use something like this to reduce the noise and it has worked for many people already, there are reviews about them online and even few videos on YouTube too.

Pls kindly share the pic of the 3D printed adapter, all for learning sake, thanks