Lenovo T and X series are excellent and cheap as dirt used. There is also System 76. Or you could get a MacBook and boot Linux on that. Some older ones work well, I hear.
Is linux support on the M1/M2 models as good as linux support on x86 laptops? My understanding was that there's still a fair bit of hardware that isn't fully supported. Like, external displays and Bluetooth.
Or more detailed results at:
https://asahilinux.org/docs/platform/feature-support/overvie...
I have done triple booting of MacOS, Linux and Windows on an old Mac Mini, and it was a nightmare to get them working, but worked well once set up.
I think well known brands and models of PCs are better for such alternative setups, rather than obscure PCs.