Super G said:
Looks a little obesse. That will no doubt affect the monitor's behavior and make it a little calmer but is not healthy.
If this is you first monitor, I would recommend getting ackies (V. acanthurus). They stay smaller, have tons of personality, and you're guaranteed to get CBB because its illegal to export them from Oz. Niles are imported like crazy, so your chances of getting a healthy one would be far less than buying CBB. They also get HUUUGE and are generally very skittish/aggressive. There are exceptions to that rule, but those are few and far between. If you went with a nile, odds are it would end up being more of a display lizard. Savs would be, in my opinion, a better choice but are also imported like crazy, so I don't know if I would buy one of those either.
If you were looking for a larger lizard, I'd recommend blackthroats (V. ionides) or whitethroats (V. albigularis). They are more tolerant of people's presence, which I think is important when dealing with such large, dangerous lizards.
It's your call though. Just remember, that kept properly with the right temps., food, etc, any species of monitor has the potential to be aggressive and not take well to handling, so even though niles are more notorious for it, savs can be just as aggressive. Just my $0.02.
Best of luck though with your decision. They are great lizards to keep, very intelligent, and still rewarding even as display specimens.
I'd check out these websites if you havent already. They have great information on monitors.
This website (Pro Exotics) has some great caresheets, FAQ's, and also sells monitors.
http://proexotics.com/main.html
Kingsnake.com has a good monitor forum with real knowledgeable people who would have some good input.
http://forums.kingsnake.com/forum.php?catid=55
Varanus.net has a forum that typically covers more advanced issues. Not so many noob questions, but a lot of the people who post are the same from the Kingsnake forum.
http://varanus.net/