How to select the correct CM choke?
There are several things to consider here.
First of all, the applicable frequency. It's not depending on the data rate as you think, but rather it's  depending on the signal rise and fall times. Usually this frequency is at least 10 times higher than the base data rate dependent clock frequency.
I'm not sure if CM chokes have a specified resonant frequency. They are intentionally lossy components like ferrite beads. You need to select a part that has as high an impedance as possible within the frequency region of operation.
As mentioned in the comments, beware that the data signal is indeed differential or the signal integrity will suffer severely.