Try a look at arctic cooling F12 pros. About £3-4 each, very quiet, and shift reasonable air. Admitadly cannot compete with my scythe kama jyunis with a controller, but they cost more than twice as much. I've been very happy with them.
Might be worth buying one just to try it. I have gotten mine from both www.shineyhardware.co.uk and Feverpitchpcs (ebay shop). I have used both shops a number of times.