I get annoyed by sound too, my tips (I know you've done some of this already, this post is for everyone's benefit):
- go in the bios and put fans on quiet mode. I've always had asus mobo, dunno if it's the same on others.
- get a case with quiet fans. The quietest case I've owned is fractal define s.
- get a cpu cooler with a big heatsink and big fans (no pump noise). Don't overclock cpu.
- get a gpu with a big heatsink and big fans. I prefer asus strix, pricey tho. Buy the non/least overclocked version. Don't overclock gpu.
- put the pc as far away from you as possible, e.g. on the floor under the desk. If cables aren't long enough buy extensions, or wireless peripherals.
- never buy a mechanical hard drive or optical drive.
- over-provision the power supply. e.g. if you think you need 650W get 850W. Buy a quality power supply, never skimp on the power supply. E.g. seasonic, corsair.
- clean the pc regularly as needed, especially when the weather gets hotter, with canned air, get all the dust out of the heat sinks. hoover the case's dust filters.
- make sure intel speedstep (or whatever they're calling it now) is enabled so the cpu isn't running at max clock constantly. You should see the cpu speed drop when idle in task manager.
- if cpu/gpu usage is around 90%+ consider changing the workload. e.g. turning game settings down.