Besides the already mentioned Star Labs and System76, there’s also Insurgo, Nitropad and NovaCustom.
As for an exhaustive list on the matter, unfortunately, I don’t think something like that is out there. Though both Canoeboot (formerly known as Libreboot) and Dasharo do have their own respective lists.
Again an association is made between butt plugs and Arch users. I wonder if moving forward showing a collection of butt plugs will become the next “I use Arch, btw”.