Sorry, but after a rather unpleasant experience as a young child myself trying to do exactly what you are considering doing, I ceased being a supporter of the idea of forcing multi-species of any animals together into one enclosure, unless you are talking about a VERY large one. Like the size of a bedroom or so. Lots of animals get stressed out even being with more members of their own species, so you have to keep a lot of visual blocks in the cage so they can feel like they are at least out of sight of a "stranger". And lots of reptiles and amphibians will happily eat anything else that they can overpower and shove down their throats.
If you stick with amphibians and maybe pick something more arboreal than your fire bellied toads, that might work out for you. But make sure that the sizes of all the inhabitants are roughly the same. Otherwise the smallest will likely mysteriously vanish one day, and the larger ones will look particularly fat and happy.
I believe the idea you are hoping for would be to come up with something visual pleasing and safe for all of the inhabitants. Having a bunch of animals in a small enclosure where you can't see any of them because all of the inhabitants are afraid of everything else that is not them, would not be much fun for you. The idea you are probably envisioning certainly seems appealing, but the reality of getting what you want will not be easy, maybe even not possible.
Bear in mind, too, that the more complicated you make an enclosure, the more difficult it will be to clean regularly. So you will quickly tire of the responsibility and work load, which will eventually produce a very unpleasant living environment for your captives. You will wind up putting off that cleaning longer and longer each time as you tire of the constant regimen you got yourself into. Warm and damp environments are very difficult to keep fungus and molds from overtaking it. Animals pass waste materials that easily produce fungus, not to mention any number of pathogens that other species might be more susceptible to than the original hosts.
Unless you have a lot of experience under your belt taking care of relatively fragile animals, I suggest that you start off small and simple and make things easier on yourself in your learning curve. Opening up a cage to find dead animals in your care will most certainly ruin your day and leave a lasting impression. As I indicated, if you are new at this, I would hate for your first experience into this stuff to shatter your developing interest. And nothing kills budding enthusiasm better than killing your pets by making a mistake in judgment.
Good luck!
