No, you don't have to uninstall CCC in order to use ATiTool.
As for ATI Tray Tools, I'm not sure. I think you may have to uninstall CCC to use it. Most people just use ATT as a CCC replacement, so I assume that CCC should be uninstalled for ATT.
I think you can get ATiTool from it's official support website at
www.techpowerup.com and you can get ATI Tray Tools from its english homepage at
http://www.guru3d.com/article/atitraytools/189/
You can probably find both of these on DriverHeavenDownloads, but don't quote me on that.