I remember hearing about System76 a while back. They manage Pop!_OS which comes preloaded on their stuff. I don’t know much more than that. If you are mainly looking to replace your laptop because you don’t want to switch to 11, you could always try out Linux on it with a live USB. Basically you format a thumb drive to act as a boot drive. There are resources online on how to do it and it’s pretty simple. It doesn’t mess with your current install. If you like it, you can fully install it later.