SamacSys provide a large online component library that supports a number of different PCB design tools and they have now added full instructions for using their library with CircuitStudio. The parts are free and it's great to see support for our favourite PCB design tool.
Online library - click here
CircuitStudio integration instructions - click here
One great feature of the component library is that they will create parts on request - click here.
Note that the current integration method uses the Eagle library format so always check results after importing, as with any CAD package never assume data imports are going to be 100% accurate.
Please note that componentsearchengine.com is a third party product and is neither endorsed or recommended by Altium or element14.