Which is a better lizard in your opinion and facts?

Ok so I am thinking about getting a WD(water dragon) or a bearded dragon. The reason I don't want the BD is because they eat so much. Do WD's eat more? If so, how much more plz? Can an adult female (females get smaller) be housed OK in an 120 gallon tank? I know where I can get one a bit higher than normal. Can they have a UVB bulb instead of a big tube? Is a 5.0 UVB bulb powerful enough? Also, do they have to have a big place to swim iin their enclosure or is a bathtub swim OK? I know what I'm getting in to and I'm asking ur opinions. Thanks :D