Well, it'll have a standard magnum bolt face and magnum length action, so that'll limit your practical choices a little bit.

If you are set against another .30cal, I'd suggest that you rebarrel it to something like 7mm Mag. By selecting a good custom barrel and having the necessary work done to the action (blueprinting, truing, etc...), you could have a very accurate custom hunting rifle.

If it were me, I'd stick with the .300 Win Mag. Absolutely nothing wrong with the caliber, and it'll handily outperform your .30-06 (with the associated cost of increased recoil).

Mike