1080p 60FPS should be possible on that rig, but you'd have to turn some settings down to get it, the Radeon HD 7970 isn't the strongest GPU anymore, though 1080p 60FPS should be doable without too much trouble on Battlefield 4, Battlefield 1 it's hard to say, the game is still 6 months away.
As for overclocking, that is going to depend on what kind of CPU cooling you have, and what kind of motherboard you have. Cheaper motherboards with weak power phases are going to have trouble with overclocking.
If you haven't built this system yet, I would advise against getting an AMD build at this point in time. AMD's Piledriver CPUs are nearly 4 years old now, and in most games get beaten out by Intel's current Core i3s. Battlefield is something of an exception to that as the Frostbite engine is one of the few engines that scales beyond 4 cores. Even so, the AMD build has no real upgrade path and AMD's processors do tend to struggle in some newer games that don't use the Frostbite engine, so that makes them not all that great if you want to play something besides Battlefield.