Short answer... no I would not recommend you get a Monitor nor a Tegu.
Both are large growing and long living creatures that require a lot of time and attention. More so than the average person is willing to offer them on a consistent basis.
But if you are determined, then read on
Before making a decision there are a ton of questions you have to ask yourself. There are also a lot of species you need to consider. Each species will have a particular list of pros and cons.
I personally chose to go with an Argentinean Black and White Tegu. This choice took a lot of investment on my part but has been worth every minute/penny of it.
I had to build an 8' long cage as it's indoor enclosure and choose to arrange for a large outdoor enclsoure for summer time as well.
The dude eats a lot (4~8 ounces of food 5 days a week) which can get expensive. I buy frozen food in bulk to keep the price down but that means I have hundreds of dead mice and baby chickens in my freezer.
The most important detail though is to remember that these animals are going to live 20+ years unless you kill them sooner. How many things in your life so far have held your interest for 20 years? Another way to look at it is consider the changes your life will go through over the next 20 years and try to foresee what obstacles will interfear with your commitment to your animal.
Lizards like large Monitors or Tegus require a lot more personal time and attention than large snakes, and also require larger enclosures (pound for pound).
Keep in mind that sub par housing, handling or feeding usually results in an angry animal. And being the owner of a 4', 12 lb lizard, trust me, you don't want to try to house an angry adult tegu
All I'm saying... is think the decision through and don't bite off more than you can chew...