"I will do my best to shoot lots of North American big game with it, but am not sure I will ever end up in Africa. Something about dropping huge cartridges in the chamber and closing the vault is just awesome"
A .470 or .500 N might be too big for the majority of North American big game.
Perhaps you may want to consider something smaller, for example a .375 H&H magnum as an all rounder. You can shoot every animal on earth with a .375 without ever being over- and only rarely undergunned.
-------------------- James Etherington-Thorpe - a man's reputation can be known by his words. Read Mr Thorpe's comments and judge his character by his own words and attitudes.