I'm thinking of getting a laptop to run Linux on. I've heard Lenovo is generally well-supported (particularly models that come with Linux pre-installed).
Is there any particular hardware I should watch out for / avoid, and / or prefer? Any other brands / models people would particularly recommend?
You can check out https://www.tuxedocomputers.com/. Their computers are designed with Linux in mind and come pre-loaded on Linux. Plus they're all modular, so you can actually take parts out and replace them if you want.
I also have a laptop from Tuxedo. It works fine and is maintainable but had a swollen battery after about 3 years. They are using barebone laptops that you may be able to order from Asia yourself.