I've also used a (2014) x1 carbon with Linux for a long time and can recommend that series. Just not the 2014 one, as it has a crappy touch bar instead of hardw

I've also used a (2014) x1 carbon with Linux for a long time and can recommend that series. Just not the 2014 one, as it has a crappy touch bar instead of hardware F-keys. But the Linux support is great. I've often thought about upgrading, because of the non-standard keyboard layout, but the performance is still great so I can't really justify upgrading it yet. I bought it for around 1k euro back in 2014, so I think you'll probably find a later generation for less. It's a great laptop, the only drawback is the fact that the memory is soldered on the Mainboard along with the CPU, so if it breaks or you want to upgrade, you'll be out of luck. My memory did fail after 2 years and 10 months, but I still had 2 months warranty with on-site replacement, which was great. I think they lowered it to 2 years now, and no on-site support, so keep that in mind. It's a real trade-off.