Wouldn't any of these work?
http://www.wowinterface.com/forums/s...ad.php?t=21199
/nui hud cooldown
This option toggles display of in-HUD spell cooldown bar, cooldown alert messages and cooldown sounds on and off.
/nui hud cdalert
When the in-HUD spell cooldown bar is enabled, this option turns the display of ready messages on and off.
/nui hud cdsound
When the in-HUD spell cooldown bar is enabled, this option turns the playing of ready sounds on and off.