I have found the answer to my question. I can use a backlit keyboard on a non-backlit Dell. It has a separate cable for the backlit so it's just a case of folding and taping it under the new keyboard.
I was a bit worried that it was incorporated into the main keyboard wiring.
I have a Dell Inspiron 5565 with a broken keyboard that has no backlight. Can I use one that is backlit instead? I understand that the backlight won't work but is the main connection the same as I am having a hard time finding a non backlit version.