I'm Parge from the Bit Tech forums, but I just registered to reply to your post.
You want silent?
You might want to take a look at the Mcubed BigNg fan controller. I recently did a user review focused on watercooling, but its relevant to air cooled rigs too, and in addition, another of our members has done a user review focused on air cooling which you can find a link to in the first paragraph.
Here is the review http://forums.bit-tech.net/showthread.php?t=230727