silent psu

Hi, I'm looking for A power supply that is Dead silent most of the time and will fit into a Meshify C., My total system powerdraw is around 400Watt at maximum My motherboard is b450 Mortar max 1x24 ATX pin 12V 1x8 ATX pin 12V (Cpu) GPU 8-pin I considered Seasonic Focus Plus 750W If...