In the same way that there might be too much overlap with a 6.5-284 and a .280AI, I think you might find the same with a .280AI and .30-06; but a .338-06 would give a sufficient 'step-up' for elk, moose, bears, boar, etc.

9.3x62 wouldn't be a bad choice either but I think I'd build one of those a fraction heavier...

Fun having these choices though!