You will need substrate that the monitors can dig in that will make the height of the cage a lot less than two feet tall. If you mount the lights inside the cage that will give you even less available height. Monitors are the most resource intensive reptiles to keep. In fact keeping reptiles is mere practice for being kept by monitors. They need room to climb as well as dig and with the high basking temps required 135°+ room to be able to avoid hitting the basking lamps.
You can mount the lighting outside on top of the cage. Low wattage lights arranged in a row are superior to single large wattage lights. You can also place the cage over a trough with the floor cut out to add depth. The cage would not be suitable for any monitor over 2 feet long due to the 2 foot depth. The cage will need to be able to retain heat and humidity and so far this is just the beginning. As far as rudicollis aka black roughnecks go that cage does not provide anywhere near the height it needs for climbing. Please remember arboreal does not mean horizontally challenged.
Digby Rigby
balboa28279@mypacks.net