Maybe try a Steam Controller? I've used the OG one. I think the device itself registers as a keyboard. Its trackpad controls the mouse cursor and the triggers act as the various mouse clicks.

If you are running Steam in the background, one of the buttons triggers an HUD keyboard, where the left trackpad types keys on the left side of the keyboard and the right trackpad for the right side of the keyboard. My guess is the new controller works the same way.

Also, some media center software, such as Kodi, have gamepad support. So a gamepad will feel completely natural to control it without having to resort to using the mouse and HUD keyboard.