If you want to check that a machine you’re buying is compatible with Linux, a good place to start is to google how to install drivers for the computer’s components on Linux. Check the common problem areas (WiFi, graphics, sound, etc.) and see if you find lots of other people complaining about those components. If you find evidence that a driver is available, or you can’t seem to find any info either way, it’s probably fine.
I can’t really answer the question you had regarding this site you found, but that is my general strategy for checking Linux hardware compatibility.
Also make sure that the retailer you’re buying from has a reasonable returns policy, just in case you get it, install Linux (or run it from a live USB, to avoid wiping the disk before you know you’re good), and discover something doesn’t work.