I have a Xencelabs pen tablet + their Quick Keys peripheral. I can't seem to find any documentation regarding specific support for it on Linux.
The official driver does nothing for usability under Gnome on Fedora 42. Removing the driver made it work better, but it was still finicky. I've since switched back to KDE Plasma, and the tablet works pretty well out of the box. There's no way to configure the buttons on the tablet, and I don't know what they do, if anything. The pen has 3 buttons but the config only recognizes 2.
I'm hopeful this means better support is coming. It kills my motivation to use it sometimes when functionality hits a snag.
I have a Ploopy trackpad, and I absolutely love it. That said, it's not wireless, so OP might not be into it.
It's about the same size as the Apple trackpad. A big surface is a must for me, so this is great. I think the "active" surface is a bit smaller, but I don't notice it.
The responsiveness is glorious. I have LMDE on a Surface Book 2, and the built-in trackpad is shameful in comparison.
There's no physical click. You get tap-to-click only. The texture is noticeable, but for me, not in a bad way. Perfectly smooth trackpads can get a bit sticky over time or if you have sweaty hands. I suspect the fine texture on the Ploopy won't let that happen the same way.