https://www.shoperb.com - e-commerce platform

That's super cool. Do you publish your process of building these anywhere?

Appeal was simple - at the time of peak Hackintosh (with Intel CPUs and Nvidia GPUs), you were able to get much better performance both CPU and GPU level for fraction of the price while still having MacOS experience (as it brings together best of both the GUI as well as Linux terminal functionality). The overhead of having to mess around with updates was well worth it at that time.

Your question doesn't directly indicate which problem you are trying to solve. It would be helpful if you would mention the hosting provider as their service offerings do differ.

If you are trying to solve storage reliability for single mail server then creating a file system level failover would be way to go as mentioned previously (LVM, soft RAID over multiple volumes, etc).

If you are trying to solve mail service reliability/failover then adding second mail server would be helpful. In that case you can use dsync (does master/master sync) to keep emails on both servers in sync.

When you look at self-hosting instructions then it would be great if it would be one that does not require Docker in your stack. Installation shell script would be even better.

When you are saying that you want to own the entire checkout experience, what exactly do you mean? Do you want to own everything related to processing credit card payments, including card data storage etc? It would also good to specify where your company is located.

We've had good experiences with Braintree, Adyen, Stripe and multiple other payment services for our customers at Shoperb (www.shoperb.com. It does sound like the problem you are facing may be technical implementation related. Have you done a custom implementation or using what Stripe provides out of the box?