Apple sells an external trackpad. But AFAIK it requires the computer to have Bluetooth. Not sure how well it works with a non-apple os, though.

I suspect it does not work well outside Apple world. And that's kind of the thing with "I want Apple hardware but with Linux software": Software is actually important in the user experience with the hardware.

Maybe, but also Apple trackpads are physically better

The Apple Magic TrackPad works well on Linux, both via Bluetooth and USB-C. I used one for a few years.

Interesting. Are multi-touch gestures supported ?

(like these: https://support.apple.com/en-us/102482 )

I don't know about the magic trackpad specifically, but on my HP Elitebook I can use gestures. I'm running i3 and it doesn't support much out of the box, but I was able to configure stuff using libinput-gestures.

More info: https://wiki.archlinux.org/title/Libinput#Gestures