Going for -
3x GeForce GTX 1060 Phoenix GS 6GB (will buy 4th in the future)
1x Intel Pentium G3260 / 3.3 GHz processor
1x EVGA GQ 850W 850Watt 80 PLUS
1x MSI Z270-A Pro S-1151 ATX
The Pentium G3260 is still an LGA-1150 processor.
Pick a processor from this list: https://us.msi.com/Motherboard/support/Z270-A-PRO.html
Pretty much any listed Pentium or Celeron processor will do the job. You're really looking for low power draw & low cost. (With a small rig, I doubt you'll hit any limitations on PCIe lanes.)
Okay, i choosed the Intel Pentium G4400 / 3.3 GHz processor S-1151.
Do you think I will do some profit mining ethereum with 4x GPUs?
That's all speculation. You'll have to do your own analysis based on Ethereum prices, your expectations on difficulty changes, your electricity costs, etc. I can't be certain that you'll ever earn back the money you spend on this rig, or if what you end up getting will be greater than if you just bought crypto with your $1233 and sold it later.
Of course, I mine, but power is cheap where I am and I'm in it for the long haul.