If you still want 92mm fans, I would go for Scythe's S-Flex line over the Kama series:
http://www.jab-tech.com/Scythe-S-FLEX-SFF92C-92mm-Silent-Fan-2000-RPM-pr-4445.html
I have 2000RPM version of the Kama that you first linked, and as good as the airflow is, there is this distinct motor ticking noise where even undervolting it using my fan controller couldn't even get rid of it. Picture a regular house fan and sticking a piece of paper into the spinning blades - that's the sound that I heard from my fan. Granted I only have one so it could be a defective fan but I have read on Scythe's own forums that the S-Flex line, in general, uses a higher quality version of the Fluid Dynamic Bearings from Sony. My own experience now with 3 of the 120mm S-Flex G confirms the absence of any motor noise. So if you're looking for something that lasts a while check out the fan I linked. There are other speeds as well, I just happened to choose the middle of the pack version.