Ryzen 7 2700X

Solution
The 2700x paired with the 1080 ti will be fine for any of today's monitors, particularly at 3440x1440p as the stress is moved to the GPU. You could run a 2600 and would not see any real world difference.
At 3440x1440 you are pushing about 5 million pixels. That means it is harder on the GPU than 2560x1440 but easier on it that 4k. You most likely won't be able to have a 100fps average across every game, but your experience should be good, especially if you have G-Sync.