Original Canon C300 Mark II owners with the clam-shell monitor can easily add Touch Focus with the Touch Focus Upgrade Kit.
Canon C300 Mark II EF Touch Focus Upgrade Kit Includes the following items:
You’ll re-use the UN-5 cables that were supplied with the C300 Mark II.
You’ll need to update the C300 Mark II firmware to enable support for the LM-V1:
Here’s a video from Canon that shows the Canon C300 Mark II Touch Focus: