My advice would be to not attempt to keep Croc monitors, but instead, something just like them, but smaller. Like Bluetails or peaches or something along those lines. Peachies would BARELY fit in your cage.
For instance, you want to put a monitor that gets 8 ft in a cage thats 4 by 4 by 8 foot tall. That should never ever enter your mind. You need to be much more aware then that to attempt to keep such a species.
Also this stuff about how dangerous or aggressive croc monitors are is a totally naive way to look at them. They are not mean or agressive, THEY ARE SHY. They are afraid of every thing that moves or is different. Shy animals need seclusion. Where are they going to find that in your cage? Not having that is VERY stressful to them and its this that causes them to be dangerous. They do not want to bite. They are full of fear.
Of course this is pretty much the same with most of these types of monitors.
What scares me is, what makes you think you understand these animals? Is there something I am missing? Why do you think you should start at the top, what? are going to work your way down. Why not start at the bottom and work your way up to this species. You know, something common sense, like start with the least difficult and move to the more difficult as you gain experience.
I don't read anything from your posts that tells me your ready or experienced enough to keep Croc monitors. In fact, what I have read is, the exact same as many who rationlize their thinking to keep and monitor they will destroy. Yes, it will not be you thats harmed, it will be the monitor. Another error in your thinking.
My crocs were kept poorly(to small of cages) and I had them in indoor/outdoor setups. The inside is 4ft deep, 8 long 8 high. The outside part is 10 by 10 by 8 feet tall. Yup, too small.
The point thats fuzzie here is, these are not snakes, retic or otherwise. These have legs and use them. They can move across a football field in seconds, a retic would have to take a bus. Try and understand that. Large monitors can move hundreds upon hundreds of yards, on a casual walk, in a few minites.

Cheers