Your desire for iron sights will limiting your choices a little bit. As for .30-06 or .308... I'd go with the .30-06 if you will also be getting an M1 garand. .308 will give you the flexibility to add an AR10 variant later on without adding another caliber. If I were in your shoes, and needed 1 rifle to do a lot of different things, I'd go with the Ruger GSR in whatever barrel length you prefer.
All around: Ruger GSR
*Incredibly versatile, comes with irons.
Hunting: Ruger American
*It is extremely light, accurate, and it's far cheaper than every other option I've listed.
Cool: M1 Garand in .30-06
*Way too fun to shoot, is a piece of American history, but it will be impractical for hunting
Tactical: M&P10 or SR762
*Easy to customize, accurate, semi-auto.
Odd that a lot of my suggestions tended towards Ruger. Not a brand loyalist by any means, I just really think those are good picks.