Motherboard/CPU recommendations - Simple media server build

[ZenBuddha]

I have an unraid media server right now that won't post.  I'm still troubleshooting but figured it might just be time to upgrade.  Here is my current configuration.

 

ASrock Z75 Pro 3

Intel Core i5-3570

32 GB DDR3 RAM

LSI SAS 9207-8i Storage controller

Nvidia Quadro P2000

Thermaltake Toughpower Grand 850W

 

I use all 6 SATA ports on the motherboard and I have 4 variable speed fans.

 

I was considering getting a motherboard that would support the same CPU and RAM but obviously if the problem lies with one of those components I'm wasting time.

 

I run a typical plex stack with dockers for media download/management.  I have a couple of one off dockers like Home Assistant and a Unifi Controller, but nothing that requires a lot.  No VMs.

 

A quick look at Newegg and I came across this guy:

ASRock B365M Pro4 for $85

or does it make sense to get something that supports the Z390?

MSI PRO Z390-A PRO for $130

 

2x8GB DDR4 RAM for $85. 

Do I need 32GB? I think I have 32 right now just because someone gave me some extra.

 

And then CPU...

Intel Core i5-9600K Coffee Lake 6-Core 3.7 GHz  for $215.   

 

Guess $500 ain't bad considering my current setup has lasted several years.

 

Would appreciate any feedback or recommendations on components.

 

Thanks!!