FWIW, I'm in a similar situation right now. I was able to massively decrease noise (and air flow) by switching to Noctua NF- A4x10 FLX fans. As long as my workloads aren't sustained temperatures are fine and noise has from gone ~70-80dB to ~40dB, with the power supply fans being the loudest part now.

Upgrade took me an hour and cost $80 via Amazon.