Okay here's the thing, of the top 23 most poisonious things in the world, 21 come from Australia.
Red bellied black might not kill you but, as that article says, you'd probably wish you were dead. Apparently the pain is very up there with the best of em.
However if you want to die quickly try one of our fierce snakes or Taipan-its good for 4-6 hrs without treatment-then I think you're pretty screwed !
As a guide your rattle snake, just doesn't cut it and your water mocossan comes in about #25
If snakes don't do it for you- maybe you should try our funnel web spider - they'd kill a black dog !