You didn't say which 30 days... if it's October, I would pick Michigan, assuming shadow has left any game there at all... :-)
Seriously, I grew up there, and I think I could go in any public forest and live off the land for 30 days. I might take the Cometa or the RWS34, and skip the other gun in favor of a fishing rod. Nothing like a balanced diet.
If I could have a tank and fills, I might opt for the Marauder, but I don't have a pump. I would hate to spend 30 days on 25 shots!
Michigan is a sportman's paradise, 6 months a year (if you're not hung up on legal seasons, you are talking survival, right?). April-June and September-November, it's the place to be.
In the off months, I'm thinking Hawaiian islands, something like that... I have actually hunted in South Australia and while it was interesting, it wouldn't be my first choice. If you really like rabbits it might be an option because they have huge European hares in abundance. I prefer squirrel.
I don't think they have snakes in Australia? At least not poisonous ones. There are some nasty spiders but no worse than CA. It's the wombats, god help us the wombats... nasty buggers, like a rectangle of gristle....