My Xbox has an NMB fan model number: 2810KL-04W-B50.
A google search pulled up that it is 33.5dB, uses 2.16 watts, 180mA, 3800rpm, and moves 52.8m3/hr (I think that's near 30CFM).
The GPU fan is a AD0412MX-G70. 19dB 5.7CFM.
The "guide" on how to make your Xbox silent is very questionable. Sure it might work fine in cooler climates but the author recommends replacing the main fan with one with a much lower air flow. I would not want to try that in Australia.
From what I understand, the GPU hasn't changed much in the 1.1 Xbox, being the same die size and I would assume having a similar heat output. Obviously it can handle a passive heatsink quite well and in warmer climates. I'm currently scouring the web for a suitable replacement. If I can't find anything then my FOP32 is going to get the chop.