Apologize for the delay,
This one is about the only one I could find that didn't have an outrageous price.
I'd recommend maybe a couple of different things. The shroud may be what is causing most of the noise and the heatsink itself looks like a fairly decent one. Maybe try removing the shroud and use zip-ties to mount the fan to the heatsink. You might want to have it blowing towards the exhaust fan. Unless they have that one set up as exhaust??? I'd hope that one is pulling in fresh and another is exhausting though.
If you just want to replace the fan because the fan is getting noisy with age then those wire adapters are usually fairly easy to rewire, it's just knowing where the wires go that is the big deal.
I was never able to get an exact size on the fan so can't offer any suggestions to you. Usually the quieter the fan though sometimes the less rpm it will have also so you may want to look at that. Just compare the cfm which is how much air the fan will move the dba which is how many decibals the fan puts out. Those are the big two. You should be able to find reviews maybe also. For a google shopping search of what you want to find use pwm fan.
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