For anyone in interested in building a silent PC, I have some simple advice: use a Noctua CPU heatsink and Noctua case fans. They are whisper-quiet, and I spent < $100 for all the fans in my system. They are the most premium-feeling computer product I have ever used; the CPU heatsink was very heavy and solid, and came with all the tools needed for installation including a screwdriver and thermal paste. Highly recommend, 10/10.