Get a .375 H&H and don't ever give it another thought. Unless, that is, you want to become a caliber collector (my basement looks like a miniature version of the Brownell's, Inc. warehouse).
That is also my very first thought, when I read this australian thread starter.
Put one of these 375's (375 H&H, 375 Ruger, 376 Steyr, a.s.o) into Your locker and You can go anywhere and hunt anything in the whole world including Jurassic Park.
I personally would go today for the 375 Ruger, because it hasn't got the Magnum ring (like all H&H shells) and it closes in the chamber on the shoulder instead. Great start for easy reloading with highest chance for precision!!
So let's visualise this one for a minute, my humble advise is and Your fiiiiiirst step should be:
Sell all Your other guns and get a wellmade, good fitting 375 Ruger (why not buying a used Ruger gun anyway?) for all Your outdoor action and reload, shoot, hunt and have fun. After some time You will handle Your gun , if when never ever used anything else. So it's finally
one real good gun,
one real good mounting and
one real good optics. Now You are the king of the jungle.
Drop them all with one good shot ! No matter where, no matter how, no matter what. Aaah, I like it easy !
Sure, recoil will kiss You in the start, but that's part of the deal, You take the punch, the buck the bullet. Better than the other way around. With the time and practice, You'll get used to it for sure.
(You have a wife ? It's about the same !!)
Not convinced yet ? Then look here: All sorts and weights of bullets are plentyfull available, lot's of powders will do, tools and brass are cheap and no problem to get hold of. Damned, I should go sell guns .....
) !