The Bluetooth card and especially the extension cable for the iMac G4 is very difficult to find, and not the easiest thing to install once you've found one. You have to remove the logic board as it's located underneath. I've removed/reinstalled one, and will link to some photos.
There’s an ancient D-Link USB BT adapter that was ‘blessed’ by Apple with an official firmware replacement. It keeps it live when asleep, so a connected keyboard / mouse can wake the computer up. A normal BT adapter can’t do this. This is the easiest / cheapest solution (about £10).
There’s an ancient D-Link USB BT adapter that was ‘blessed’ by Apple with an official firmware replacement. It keeps it live when asleep, so a connected keyboard / mouse can wake the computer up. A normal BT adapter can’t do this. This is the easiest / cheapest solution (about £10).