I have a Tsunami LC-A400 Watt. ATX, as the model number suggest it's a 400 watt unit and is whisper quiet. Cost £40 about 8 months ago and worth every penny, maybe cheaper now.
CPU fan is "Globalwin Twin" consist of two fans on the heatsink, also whisper quiet £25, the only noise I hear from my system is a gentle hum from the hard drive, " Maxtor 80g. fluid bearing drive. J.