Okay, so I'm getting a GTX 980Ti, and will have 16Gb ram, however I only have an I5-3470, I intend to run games like witcher-3 and Fallout 4 in ultra 1440p, Will this be sufficient? What will the CPU Bottleneck?
Your CPU will definitely bottleneck that graphics card. To run the 980ti card without problems you'll need to look at the i5 4690K / i5 4770K / [Other Unlocked i5 Haswell Lineup].
You'll still be able to play the games you mentioned above, though perhaps not on Ultra.
The i5 3470 is equal to the i5 4460 in terms of performance. At 1080p there might be a bottleneck in CPU heavy games like GTA 5 but at 1440p I think you'll be fine. Don't think it would be drastic enough to warrant a CPU upgrade.