I got a Geforce GTX 960 with an i5-4590. It runs everything we do great, 40-60 pretty strong, dependant on what's going on, but doesn't really drop noticeably during those extreme engagements.
Get a better processor (i7 variant) if you can afford it. And make sure to get a decent processor heat sink (cpu cooler) 30$ or more.
Work around these specs and you'll be pretty happy. I run everything on high-ultra no problems.
I've heard bad things about the 980ti.
EVGA 980Ti here, no problems so far. There is a lot more coil whine under heavy load than I'm used to, but with my headphones on I can't hear any of it.
Kiefer do you have a reference cooler or ACX? On my 780ti reference cooler it has always had coil whine over 400fps.
I can't speak to that card, but when I first got my 7950 it whined like crazy. A few months later it stopped or decreased to where I can hardly hear it now....also helps that I got a nice and quiet case. Fractal design S.
It is all luck of the draw when it comes to coil whine, usually the more power hungry the card or depending on what application is using on the card, you may experience a great deal of whine. Unfortunately Arma is one of those programs.