Here are some of my opinions on the matter:
"Alright I was thinking about getting a Monitor ( an Argus preferably )"
"-Whats a good beginner Monitor ( I have experience with Leopard Geckos, Box Turtles and Desert Tortoises )"
I agree with Scott, as most will recommend ackies for first-time monitors. They are very helpful in learning monitor behavior, which is a must with argus monitors. If you can't read them correctly you will get hurt, and the monitor will suffer from your mistakes in husbandry.
"-What doesnt get to big ( Around the size of an Argus preferably IE- 5 feet max )"
Again, research ackies, you would really enjoy keeping a pair. They are a much more managable size than argus.
Trust me, you don't want to have a pissed off 5' argus that you don't know how to work with. Start with a more managable species first, then move up to argus's if you truely feel you can properly take care of one.
"-What is not agressive ( Isnt gonna kill me )"
This is something that cannot be easily answered by me. It has a lot to do with the keeper's ability to read the animal and not push its limits. Ackies are considered a nonagressive species due to the fact that they are more forgiving of keepers, you would really have to do something to offend them to get bit by any of mine. My argus's are the same way, you just have to know when not to muck with them. Leave them alone and they won't mind your presence in the cage with them (cleaning,feeding,changing water, etc...), but if you break that trust with them, its hard to regain it. The ability to read the animals is why I wouldn't recommend something like an argus for a first-time keeper.
"-What can I somewhat handle ( Walk with a Leash )"
The most enjoyable interaction you can have from keeping monitors is watching their behaviors/life events in my opinion. Walking on a leash would be extremely stressful for any monitor, if setup properly that kind of "exercise" is never needed. Remember, monitors are NOT dogs. And shouldn't be treated that way, treat them like what they are...which doesn't include walking them.
"-Does an Argus fall into this category?"
From these types of questions, I would have to say an argus is not for you, yet. Do yourself and the monitors a favor and start with something easy, you'll have more fun with them that way.
Good luck and happy researching, Lance