If I were you, I would consider buying a used/refurbished 2012 Mac Mini, then you can just clone back to it from your backup.Urghh, what a start to the day. I arrived to find our 2012 Yosemite Mac Mini web server had restarted itself for no apparent reason, and our MySQL database was corrupt. Our daily Carbon Copy Clone had also failed due to a 'hardware error'. Fortunately, we have a couple of clones, and I'm confident one is good. It's been a good machine and we've got our money's worth from it.
The issue is replacing the server. I can buy a new server, but Mojave 'Server' doesn't have any of the web services we need.
I can't boot from our clone, because in Apple's wisdom, you can't boot a new machine from an older system.
Our clones are Thunderbolt 2, which the new machines don't have.
So right now I'm hunting around the office to find a little used machine which can boot from a clone, just to buy me a few days breathing space.
I then start the task of deciding what direction to take, be it Apple, Linux or Hackintosh.
I'm still not entirely sold on Linux. I installed LAMP on Mint, but it didn't work properly. I then uninstalled it, and it broke the entire system.
Life was so much easier when Apple weren't so keen to kill off features and rush out meaningless OS updates.
There are many places to find some good systems. i.e. eBay, MacSales.com, Amazon, etc.
I like the older systems - speed is not that much different, they can run older OS's and cost is sometimes half the cost of new.
I like to look for base systems and then buy new SSD's and make sure to max out the RAM.