As for the cable problem, I'm sure third-party solutions will be available shortly. For RAID 5, you'll need a third-party card. If you were expecting some big overhauls, chances are you’ll be disappointed at a first view.
This process assumes you have downloaded a local copy of the target macOS installer (10.14.6 required on 2010-2012 Mac Pro 10.15.1 or later required on 2019 Mac Pro). The steps that follow provide an overview. This setup will reduce the maximum performance levels as compared to the factory RAID 0 config, but it is possible.
