Possible New Cage for Chibi

I have a cage that is 1ft wide, 2ft 1inch tall, and 2ft 6inch long. It has a screen top and screen doors on either end. It has the same footprint as Chibi's current cage, but taller.

I was wondering if I could convert this into a cage for Chibi. Seeing as the tank is currently just sitting around collecting dust and because of the side doors, it makes a bad cage for snakes (can't really keep humidity in). So I was wondering if I can move my leopard gecko into it. If so, would I need a stronger heat bulb to warm the tank? Will the side doors prove to be a problem? Also, the screen on the doors is thinner and weaker than the tough screen top. Could I do anything to strengthen these doors so there will be nothing getting in (like my cats).

When I have my own place (rather soon) the snakes and Chibi will be kept in one room while the cats have the run of the apartment. That way they are never left unsupervised with the reptiles.