New Build Need Advice on Parts and Compatability

k.mazurk88

Prominent
Dec 26, 2017
44
0
540
Will be using for everyday stuff and a lot of AutoCAD/solidworks/mastercam and some occasional racing games. Can you please take a look at these parts and give me your opinion and any changes/ recommendations. Its going to have to be a HTCP case since i only have roughly 9" height for the case.

CPU/ i5-8400 or Ryzen 5 1600 Leaning towards the intel
MOBO/ ASRock Z370M Pro 4 OR MSI Z370-A PRO depending on case
CASE/ Undecided and need help on this one
RAM/ Corsair Vengeance LPX OR Viper Elite Series-- Im thinking about getting a single 8gb and in a month or two getting another 8gb to take advantage of the dual channel
SSD/ Samsung 960 EVO Series 250gb OR/AND Samsung 850 EVO 500GB
PSU/ Need help with this also
GPU/ Either a 1060 6gb or a RX580 8gb cant decide on which one, i have a 4k freesync monitor so im leaning towards the RX580 both are about $300, a buddy of mine was saying to buy a used 1070 or 1080 which can be had for 350-375 on ebay but am unsure how i feel about used electrical components.
Optical Drive/ Looking to get a 4k blu ray player but will most likely wait and see if prices come down alittle.

ANY advice on parts and in general would be awesome.

Thank You,
 

k.mazurk88

Prominent
Dec 26, 2017
44
0
540
why should I go with the Asrock Z370 Extreme 4 mobo?
I did not know that about the memory. So even if its the exact brand and model and speed it may not be identical?