Check this site.
http://[bleep]/care_sheets/lizards/water_dragon.htm
It has most of what you asked about. Make sure to add a kitty litter box (what I prefer using. Easy to clean and makes for plenty of soaking room.) filed with water. Lots of plants, and climbing branches. Dragons are arborel Animals and prefer to stay as high up as they can in the encloser and like to be able to hide in folliage.
I would start out with a 20 gal long to begin with or you can jump straight into a 40 gallon if you dont want the hassle of getting a bigger one later and want to give it a good healthy enviro.
Be sure to dust your crickets with Vitamins! Broken bones, shedding problems, and mutations and all sorts of other problems can arise without the use of reptile vitamins.
Not sure on total head to tail length of full length though. Anyone know?

My Website
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Just Hatched, growing fast!
Http://www.Nifty-Critters.com