Hi Leo
I have bought a little CNC machine from Vevor, just a toy really, but, gives a good idea of how things can be done. Also, slowly building something bigger and better.
The reason I mention this, is that Vevor also have laser engravers.
This link is to one in particular.
https://www.vevor.com.au/laser-engra...p_010629102294
While this is smaller and less powerful than you are after, I believe it will be possible use the same electronics on a bigger frame and swap the laser for a more powerful unit.
Of course, you would also want to build a box for it, with an interlock for the power for safety reasons.
There are a fair number of forums out there, so happy hunting.
Philip