Precisely. However getting a second 760 isn't necessarily the best option, it might be the cheapest, but you will still be left with 2GB effective Vram. I highly recommend getting a proper card to replace the current one, instead of just adding another.
Personally I would recommend a GTX970 as an upgrade, that or then a R9 290(x). With the resolutions OP has in mind it is best to go for 4GB Vram, 3GB, is going to get crowded really fast. This is coming from someone with a 7950 with 3GB VRAM, and I am playing @1080p.