I think your post is a little broad, yes the Sav will need a large enclosure, but not for a year or so. I have my blackthoat housed in an 80 gal right now, and he is perfectly fine in it. ( i do have plans to build another enclosure, but just sayin.)
Do you have cats or dogs? They get fed everyday, so that is not THAT big of a deal, as an adult multiple small rats are perfect for monitors.
If you want that sort of lovey creature that will cuddle, a monitor is maybe not for you, but Tegus, are very friendly, and very playful.
Watch this
http://www.siscoreptiles.com/tegu-attention.php