That would be cool.... I would love to have a water too, but to big for my house, i have small kids.........Wait a minute... maybe I will get one..LOL. If I were you I would go with a Red Ackie or a Black Throat.. they are the coolest of all IMO. Unless you went with a Black and White Tegu.... But do your research on them..... I've heard they are pretty aggressive.
black&whites? no they're not at all, unless they are the columbian (which really are just more skiddish), the argentine's are dog-tame.
like i said, if you don't want something that big go with a blue tegu, they look about the same and are just as tame if not more so.
my columbian is sweet as pie...sleeps with my daughter...the red needs some work though...gets a little huffy, she was a trade in..I dont think she was treated really well...missing a lot of toes and was really thin. anyhow they are great animals.
I would take your time and then decide, I have 3 Niles and I love them but they are a handful only one of them is somewhat docile (hehehe) they are a love of labor, 3-5 times a day of changing water tubs (as you know this is where they do there business) but on a side note the cages are always clean. Have you researched any of the ackies check the link out to proexoctis (where I have bought numerous animals from) http://www.proexotics.com/FAQ_answers_What...s_so_great.html good luck on whatever you get
how much space do you have??? i wuld just put the croc out of the picture for now anyway. but yeh a sav or a b/t w/t wuld be ure best choice if you want a big lizard. since u have some space u can get 1 of those instead of a timor or sumthing. but is not and u wanted a nile/water u shuld prolly go with a water. i cant really jump that far ahead because i am only experienced with savs...for now anyway