https://linuxpreloaded.com/ for a longer list

These are my favorites (EU based)

1. TuxedoComputers
2. SlimBook
3. Star Labs Systems

Tuxedo Computers can get you a very good dev laptop for ~1500€ (64GB RAM, AMD/Intel CPU, NVIDIA/AMD graphics card). If you will be working in AI, I imagine you'll need CUDA (?) aka NVIDIA.
If you don't go for anything on linuxpreloaded (which I wouldn't recommend), it's good to check whether what you're buying has linux hardware support by checking the Linux Hardware DB. Even if you don't look, it'll probably work, but better safe than sorry if you're going to dump 1/3 or 1/2 of your months salary into something (depending on where you are).

For a distro, I dunno what level you are, but Distro Chooser can help you out with making a choice. My recommendations:

linux beginner

Linux mint. nice desktop environment, looks like a mashup between windows and mac, still missing advanced options, but quite customisable. comes with suitable standard software and cloud integrations (you can connect to a bunch of clouds), relatively up to date

Ubuntu is well-known, some proprietary companies even consider it "the linux" and only make linux versions for it. It's quite stable. However, it isn't my first recommendation anymore as they are going down a proprietary route. I'm not sure if they have ads yet, but wouldn't surprise me if they started.

desktop environment

This is the desktop suite, a bundle of packages that work well together on any distro, with its own look and feel. There are basically 3 camps:

• windows look n feel
  • KDE: is the most known, is very customisable, has an abundant amount of themes, icon sets, login screens, fonts, and a well-sized userbase. They prefix many app names with "K". Ubuntu even has a distro version called "Kubuntu" with KDE on it
  • Cinnamon: main user is Linux Mint
  • LXDE and XFCE: look closer to windows 95 and windows XP, consume minimal resources. configuration is through the interface, advanced configuration through files
• mac look n feel
  • Gnome: they are well known and source of flame wars (gnome vs KDE). windows don't have title bars, things are very rounded, not very configurable, heavily mac inspired
• tiling window managers
  • these aren't desktop environments, but sit more in the middle, they manage windows. best to watch a video about tiling window managers. they are very geeky and perfect if you love using nothing but your keyboard

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