Pretty sure CS:GO doesn't require an i7's worth of CPU. Pretty sure most games don't actively require an i7's worth of CPU. You can drop down to an i5 or equivalent Xeon if you can find one if you want. Most of your gaming performance is still from your GPU. If you know the resolution of your monitor, you can tell which GPU you probably need as well: at 1080p@60Hz, the 1070 is overkill and the 1060 will suffice. If you're going over 1080p@60Hz, then the 1070 becomes a better option.

If you want to go over 1080p@60Hz, I would personally argue for 1440p@60Hz over 1080p@144Hz. The perceptual difference between the two is immense, where as the perceptual difference between 1080p@60Hz and 1080p@144Hz is probably equal parts myth and fact. If you want to spend hundreds of dollars on maybe getting a slim advantage in CS:GO, go for it. You'd probably be better served buying a better internet package to lower your ping though, since at least that has an easily quantifiable impact on delay.

Keep in mind, 60Hz means that all frame delay can be accounted for within 16.7ms of total deviation. 144Hz over halves this to 6.95ms of total deviation. (That is, +/- 8.35ms and +/- 3.475ms respectively.)

If you compare this to your ping to any server outside of your own network (e.g. Google's 8.8.8.8 DNS server), you'll almost certainly find that it's larger than 16.7ms.

I can also assure you, it is a very slim portion of the population that has any meaningful ability to react differently to these two different rates.

Now, if you just want a smooth picture and you can actually SEE the individual frames at 60Hz when playing video games (not tearing, the actual frames), then go for it.

Otherwise, the desktop space from 1440p is very quantifiable, very usable, and very pretty.