Well, my friend makes these cooling fans and I know that if I ever needed one, I'd get it for the cheap. I once asked if anyone can assemble this but he insisted that knowledge of tube amplification and electrical power is/was important.
As far as noise is concerned, I think this would depend on the wattage. A 100 watt amp will sound louder than a 50 amp one. I haven't come across one that was completely silent.