Eli,
After a quick parametric search I found the follow list of fan controllers:
http://e2e.ti.com/support/data_converters/precision_data_converters/f/73/p/1215268/reply.aspx
I don't see any that have the option of driving up to 9 or more unique slave addresses. There is one device that supports multiple fan control, the UCD90910. This device is a ten-rail I2C addressable power-supply sequencer and system-health monitor. Twelve of the GPIO pins offer PWM functionality, and by using these pins you can operate multiple fans in parallel. This part is beyond what I support and would have to redirect you towards the group that supports the device -- Power Management > Sequencer>Ext Forum.
Regarding the second post. The AMC6821 device allows the user to program a high threshold and low threshold for the TACH. The registers associated with these thresholds can be configured to enable alarms. Any more thresholds or alarms would have to be implemented in user code. The controller responsible for communication between the AMC6821 device would have to periodically ping the TACH Register and compare against a Look-Up-Table (LUT) in the controller and trigger any condition/alarm for the different TACH/Speed levels.
Best Regards,
Matt