There are plenty of larger females out there. On average, yes, males do get larger. Doesn't mean that is always the case. Hers an album of pictures, I have a ton of pictures probably some videos. Let me know if you want more info. I wouldn't say I'm an expert by any means but I do feel very confident with my knowledge of them. http://imgur.com/a/HNtmc

I have a male, hes got jowls (big squishy cheeks). I was hoping for a male because I love the jowls but I didn't try to ask for a male or female. I haven't heard of any differences about behavioral differences, I think it just varies upon the animal and how its cared for vs male or female. Males also leave sperm plugs when they poop. I love my tegu, hes really like a scaly puppy. honestly the mininum enclosure size should be 8x3x3. some people say you can get away with 6x3 but i really believe they use all of the space and some people who use smaller enclosures have issues with "nose rub" or behavioral issues because the tegu is crammed and wants out all of the time.