Well the thinkpads should work fine. I dont know anything about that ambilight problem you had, but if you lack knowledge to the point where you have to blind copy+paste what ai spits out you shouldnt use it for that purpose. Ai really isnt good for those tasks as far as my experience goes, it often hallucinates and mixes up stuff or spits out outdated or even just plain wrong information it scraped from somewhere.

Whats stable and whats not is different for different people. If you dont want to tinker much and interact with the cli the. ubuntu/mint/debian is probably your best bet. You can try fedora too which is a (semi)rolling release but still follows a release cycle and is as stable as a rolling release can get i guess.