http://www.yankeehillmachine.com/
Yankee Hill Machine makes very high quality supressors.
They have a lifetime warranty, good sound reduction and great support.
If you are thinking of 40S&W or 45acp in the future, buy the larger cal and be able to use it on more pistols. Won't be quite as quiet on a 9mm but more useable.
They sell very well for us in Colorado.