Oh, I have the kandalf but basically the same as the armor except is has a door. I have 2 12" light I installed one behind the horizontal support frame (the one between the psu and mobo) and used a strap/tie to secure it. The other one is in the bottom under the sound card all the way to the mobo's side.
It's always good to place the lighting behind something making indirect illumination. It is also better and dramatic to see the inside glowing. You don't wanna place the cathode where you can directly see it, it would be just glary and bright.
😛