If you're asking about 'taming' a monitor, I don't think a savannah is the right choice for you. Maybe a puppy? Keep in mind you're talking about a wild animal here.

The go to first monitor recommendation is Varanus acanthurus with good reason. They stay a reasonable size, are forgiving of husbandry error and are surprisingly interactive. I just want to point out that interactive is MUCH different than 'tame'.