As babies they can be kept in an enclosure the size of a ten gallon tank. As a 3.5 ft. adult, I keep mine in an enclosure about the size of a 40 gallon tank. Any enclosure housing a spotted of any age needs to be secure--tight screen top with cage clips or a secure door. Forget the tanks with the slide in screen tops. My girl figured out how to squeeze out of one at a size where it seemed impossible for her to do so. Fortunately, I went to reach for some hemostats in a supply rack, and there she was lounging on a pile of clean snake bags.
I use an appropriate sized UTH on one side, and have provided her with one warm and one cool hide. My experience with antaresia species is that they prefer tight hides. Aspen is my substrate of choice. I also provide her with a good size bowl of water and several climbing/perching branches. She is an active adult who uses the branches for climbing and perching. The enclosure next to hers has an angled basking lamp, and sometimes I see her catching a few chance rays.
As babies, spotteds can be nippy. Just keep handling and eventually one day your snake wakes up and decides to be well-mannered--they tend to grow out of it. Mine rarely refuses a meal, eating small f/t rats--and she is a voracious rat wrecker! I feed mine in a separate container.
Best of luck with your spotted. It is a hardy species, personable, and irridescent in sunlight. Hope that the info helps you to get started.
rgds,
althea