First thing, the 7950 beats the 760, easily. Now that is out the way:
Very few games actually use PhysX. I use a GTX780, I turn PhysX on in any applicable games, and it doesn't really change my experience too much. PhysX isn't worth the performance drop. It is nice in some instances, but I would pick the higher performing card with 3GB of frame buffer (7950). You could purchase a much more expensive card, which will have sufficient performance to compensate any use of PhysX. e.g 770.
I actually said that the 7950 can beat the 770, not 7970. If you watch the video that I linked, it would have demonstrated my point. I guess it is entirely possibly for a 7950 with a good cooler to beat a 7970 with a bad cooler.
The 760 2GB would be somewhat limiting if you tried to use it on three screens. It is a card that is incredibly well geared to gaming at 1080p. The 79xx cards are a little more versatile. Good for surround-gaming, or resolutions higher than 1080p.
If you already have a gaming card that is sufficient for Minecraft, or whatever, I would wait for the new AMD cards. They are rumoured to launch in these coming months.
Otherwise, your best surround gaming solution might be the 780. It's a pretty expensive card, but if you're using a Prodigy, you cannot SLI nor Crossfire any chosen card.
Only reason to get a 760 is if you game on a single 1080p screen, and the games you play run best on Nvidia. No other reason to consider the 760. The 7950 has dropped in price, very similar price point these days. And the 79xx cards come with more free games.
The 760 has fewer Cuda cores than most Nvidia cards at the same price level, including the older 660ti, which it is replacing. In short, the 760 isn't a productivity card. Adobe software suite supports AMD. So in your given interests of running mods (more vram helps with mods. No, the 4GB 760 is not worth it), playing AMD optimised games (BF4), and potentially editing. You should not be considering the 760 at all.