Like Lindy says, there aren't many problems you can't fix with $700 and a .30/06 (the $700 should cover glass and mounts). From your list I'd be inclined to choose a M-70 or a CZ 550, but if price were an overwhelming consideration, the Vanguard would get the nod. If you have an interest in shooting with irons, NECG's excellent CZ peep sight with the ghost ring aperture, or the target aperture drilled out, combined with the brass faced patridge front sight is tough to beat, making the CZ rifle a bit more desirable than the others. The front sight hood of the CZ is open to allow light in, while still providing protection to the sight, but mine seems to put a distracting shadow across the sight, so I remove it when shooting with irons, and replace it when the scope is mounted. If the rifle will be a scope only proposition, the M-70 would be my preference if only because the CZ ring mounts are a bit limiting for locating the scope, particularly one with a long ocular, where a M-70 with a Pic rail has has all sorts of latitude.
To my way of thinking, a hinged floorplate is the single best magazine system for a hunting rifle. Blind magazine are difficult to clear should you experience a jam, while detachable box magazines can be lost, and military floorplates tend to be difficult to open and less pleasing to the eye. The complaint of floorplates opening under recoil, and dumping their contents in the dust just as the buffalo, bear, or elephant, etc charges from 30', are heard about far more than experienced. As with any problem which arises with a rifle, should a worn component fail, it only requires fixing or replacing to make serviceable. Should it actually occur in the aforementioned scenario, well, you're paying for the thrills, suck it up.