What is comparison of readout times of global and rolling shutter cameras?
The image readout rate is the frame rate of the camera in both instances.

So if your camera is 30Hz then you get a new image every 33.3 ms. It will make no difference whether you have rolling or global shuttering. 

The clock rate at which data is transferred is related to the camera functionality. 
If the camera provides uncompressed data, then this will typically be the highest clock rate.  

If the camera does compression of the data the clock rate will typically be slower.