Keeping in mind that this is coming from someone who has never kept red bellieds or death adders, I would have to respectfully disagree with Al. He makes some great points, but in my opinion, based upon my own experience with elapids vs. viperids, I find some of the medium to larger elapids to be easier to deal with than some viperids, even some of the smaller ones (sometimes, especially the smaller ones). Death adders are known for their viperid-like morphology and habits. They don't reach particularly large sizes, but have an exceedingly toxic venom. From what I've read and have been told, they tend to be slippery on a hook and are able to strike a considerable distance, maybe even their entire body length. Babies and juveniles can also be a real pain in the rear to feed. Red bellieds, on the other hand, do reach much larger sizes than death adders, but they have a much less toxic venom and seem like they would tend to be more cobra-like in their actions as far as trying to flee or attack. For me personally, snakes like this are easier to avoid bites from than smaller, more volatile ones. Maybe even better than the red bellieds, based upon toxicity and temperament, would be Collett's snakes. I've seen people going so far as to freehandle them with seeming impunity (though I by NO means condone freehandling, as eventually the odds will catch up to you). Collett's are similar in size and body structure to the red bellieds, and are, IMHO, even more beautiful, so maybe you should give them some consideration.
Like some of the other posters have mentioned, there are many other 'lightly' venomous elapids in Australia that would be much safer than any of the above-mentioned species, but I can certainly understand your desire. Since you live in Australia and presumably have easy access to AV, I won't try to push you one way or another as far as what species I think you should keep, because my opinion really doesn't matter. In the end, it's going to come down to what you feel comfortable working with and, maybe even more heavily, what you want. Try to find people you can visit who keep all the snakes you're interested in, and watch them work with their captives. Eventually, try handling a few yourself (under supervision) and see what you're best at working with. Keep us updated. It sounds like you are constructing a very nice enclosure that should suite your needs nicely. And of course, be careful.
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Chance Duncan
www.rivervalleyexotics.com