as my predecessor wrote, there is only one K1C.
This printer is really very good, there is probably nothing better on the market for the price.
The parts with PLA carbon are really great and stable

What is the latest version? There is only one K1C. Before that there was the normal K1 or K1Max, neither of which I would recommend. The latest version would be the K2. So there is no "latest" version of the K1C, otherwise it would be called something else.