My criteria for a healthy keyboard, ordered by importance DESC:
* ergonomic with split ( e.g. Goldtouch , MSFT Natural series , Adesso)
* backlit
* silent but with durable switches (there is enough noise in the world)
* Bluetooth or unified receiver for both mouse and keyboard ( e.g. Logitech )
* if there is a trackball or touchpad, there must also be buttons to maintain full drag-drop and copy-paste functionality
Rather than fuss about the switches, I recommend that coders assemble a reliable set of ergonomic components (portable LCD, keyboard) that connect to $somebox via a docking station.
$someboxen will come and go, but aim to preserve comfort and safety.