I've never had a Southern Bell Frog, but from what I've read they will enjoy a part land with plants to hide amongst, part pond-like set-up. You'll need a good filter in your land area to prevent waste and ammonia build-up, or a wide bowl in which you can change out the water daily. They like swamps and ponds in nature and they enjoy swimming. From what I can see you'll need a permit to have them if you're in Australia. I would recommend a wide tank to give them lots of space.