Here is a round-up of 120mm fans to help you decide (use babelfish if you want to translate):
http://www.matbe.com/articles/lire/1...tres/page1.php
The synthesis graphs are easy to understand:
http://www.matbe.com/articles/lire/1...res/page26.php
Add to these the Delta WFB1212M and the Adda AD1212LB which are excellent
The best idea is to try them yourself and decide which one you prefer.