RE: 7mm vs. 30-06
Where do you plan to hunt? In the open or in a dense lodgepole forest? Or possibly in between. I am of the opinion if you are looking for an all around weapon then you are looking at the light side of things. If you want to be able to take any animal within a reasonable range than you need to be looking at .30 or better.
I have killed elk, deer, and antelope with 7X57, .25-06, .30-06, 7mm mag, .300 win mag and .338 win mag all have their merits and all have their detractors but if you are trying to settle on one gun, then go with something that offers a bullet with good sectional denity and a good ballistic coefficient.
It all depends on the range you are talking about. You could knock down an elk or a moose with a .22 short at point blank range in the head or you could down an elk or a moose at 1000 yds with a .50(although I advise against it.) Your hunting condition will dictate your choice of caliber.