The fan in my dock was making rumbling noises, and the quietest replacement one I found after looking for 5 minutes was this one. It has bling bling blue LEDs, but this has no effect whatsoever inside the dock. It was cheap and very quiet.

Btw, Mark: is there a reason you used the square pattern Robertson #0 screws for the fan? I was quite lucky I had the right driver, those things are rare in the UK.