ultroz is partially correct.
The hardware cost will increse with each component ( except gpu, which will be either 980 ti or R9 380x )
The answer for your original question- if you are gaming concerened and bits of other work, then get a better gpu and a just a bit less powerful processor, mobo etc
Also, you will have to get a new psu, as the old one will definitely NOT work with your desired specs, whether its nvidia or amd.
So, get at least a 750 watt or more psu. ( it should be of a reputed company like corsair,xfx,coolermaster etc )
And for the specs, get the i7 4790k, as mentioned by geekwad, and the mobo should be a Z97A. And be sure to get at least 8 gigs of ddr3 memory ( or more if you wish ), all this coupled with your 980 ti will work fine for gaming for a couple of years before needing an upgrade.
Mind you, gaming needs better gpu than a cpu, and while the processor is important, games these days are more gpu intensive than cpu.
Cpu's only provide more ground for the gpu to work.
That's why, there is a very slight difference b/w FPS of games played on cpu's of different generations.
On Getting a sixth gen i7 you will hope to get a few more fps at the cost of getting a worse gpu, which will, in the end, actually result in worse fps than the 980 ti with the i7 4790k.
Watch a few comparison videos on #Youtube to check me.
And also compare some other processors ( I personally recommend you to get a Intel Devil's Canyon gen i7 unlocked processor )
Do tell me if you have any other queries.