if you get a snake ... then use the tank to raise feeder mice ... 
heck ... I got a little California King Snake and decided to raise the feeders myself ... now I have 2 cages and a total of 2 males and 3 females (and 3 babies left from a litter of 8)

heck ... I got a little California King Snake and decided to raise the feeders myself ... now I have 2 cages and a total of 2 males and 3 females (and 3 babies left from a litter of 8)
. no just kidding, but i agree with the geckos or a hognose snake. hognose snakes are really cool. id get one of those or a less known gecko like a panther, because not as many people have those, where as many people have leapord geckos. but what you decide on have fun with it. im sure whatever you get it will be awesome.