That would work fine. Just find a locking lid.
I second what most have said about them being a bit of a pain in the ass. Carpet pythons are bit more active and are also semi-arboreal so they are better display animals IMO. I've had ball pythons and they spend most of their time hidden....not to mention the winter fasting that most males will go through.
I'd also recommend against a fish tank....they are made for holding fish. They are very poorly insulated and it's hard to maintain humidity with the open screen top. I see so many snakes with upper respiratory infections because lack of humidity and temperature control....and dealing with that is not pleasant.
I've been trying to thin down my collection to just a couple animals lately, since I'm planning a move and whatnot. I have an adult female jungle carpet python that's about 6' now and a younger male coastal carpet python that's maybe 30" that I wouldn't mind parting with if you aren't deadset on a ball python.
If you decide you want something slightly arboreal, I have this cage that you can have for $20. The plexiglass in the front slides out and the top is hinged at the rear. It needs a little fixing up, but you could customize it and make it a very nice display tank. I never got around to doing it because I have a hard enough time keeping up with my animals in the rack set up I have. I also have some Reptile Basics radiant heat panels, which are the :crap: for reptile heating, as they are made out of nonflammable material and it's nearly impossible for the snake to burn itself like with belly heat and lights. I had a heat mat short out in the "on" position and fried a male ball python a few years ago.
