Well, in that case, I think you should listen to what the experienced members initially gave you for answers.
One thing I will say is DO NOT buy on an impulse. DO NOT get a snake just to FILL a tank.
In the best interest of this hobby, research the animal, and think LONG term. Plan on keeping it for the extent of its life. That includes a place to keep it when you go to school, assuming you are a younger person. A place to keep it should you move.
I'd say you are better off with a diurnal colubrid that is 2 years or more in a tank like that.
To me, it looks as if your question was sufficiently answered in the original post.
And it looks like somebody said King Snake. Go figure!! Its a good thought.