Welcome, this is an area that I am interested in too.
You can download all areas of the earth as digital elevation models from the USGS seamless area:
From there you need to get the data into XYZ format and I believe Wilbur can do that for you.
Once in XYZ format you will need to generate a cutter path but this is where you might have to put some effort in as you need to take into account the machine cutter profile. Normally you would generate a roughing cut with a small offset and then use a small cutter like 1mm or so to skim off the last little bit. The small cutter allows you to get the most detail but the cut pitch is very small so it can take a long time.
The texture to go on top should be easy to find though if you print it then its unlikely to fit over the 3D terrain unless you can print onto something stretchy. You could compensate for the height but I think it would be tricky. I have seen this sort of thing done with a projector facing down tho that is not a permanent fixture.
I plan on trying something similar in the future so interested in what you come up with.