Whichever calibre takes your fancy is really the answer. My .450/.400 3" NE is fine for all the above-mentioned game (although I haven't yet hunted camel with it). This game is never so much about need as it is about fun, so pick a calibre you fancy and go for it. Perhaps a rimmed one might be better. And because my calibre and the .458L are available pretty cheap new from the factory, you might want to choose something other than those two.