I got two from Amazon recently and they both work out of the box with Linux. I suspect any you can find will work. They’re standard HID devices which send multimedia key codes like KEY_VOLUMEUP and KEY_VOLUMEDOWN
This isn't standalone, and doesn't have press-for-mute, but the DasKeyboard 4 Pro has a nice, large aluminum volume knob (and a separate mute button near it). Works perfectly in Linux, along with the "sleep" button. It's part of the keyboard so it's close to your hands and doesn't have any separate cabling.