Diamond Like Coating - any info?

I am in the process of designing & building an "old fashioned" mechanical clock. In clocks as well as many other mechanisms, bearing & rubbing surfaces benefit from extremely hard & low friction wearing surfaces.

I have read that there are coatings that impart hardness approaching "diamond" with low friction. These are normally referred to as "DLC" coatings. There appear to be a wide variety of applications out there - do you have any information or pointers to help in the selection of such coatings? Are there any real Experts?

Your thoughts are appreciated

DLC is often a plasma assisted vacuum deposition coating, and normally only for the insides of hollow items such as pipes.
Unlikely to be possible for external coating of cogs, etc.