Ackies are a great starter monitor and don't attain a large size either (~24"). Easy to care for and you do not need to worry about them attaining great sizes and having to feed and house an animal that size. They have great temperaments as well.
If you are sure you are prepared to house, feed, and handle a *large* monitor, then I would suggest going with a Blackthroat or Whitethroat monitor. Both of these are relatively simple to care for but can get as large as 5-6 feet.
As for caresheets, <a href="http://www.google.com">Google</a> is a great tool
Good luck with your decision! :thumbsup: