Jesse,
I’ve never had good results with DW with external raids only single drives.
As a last resort maybe I would try. But if there is an issue like yours and its not reported as needs fixing in DiskUtil in OSX then its not an OS issue.
Plus the the pure size of raids it would be quicker to just reformat the raid and re copy the media back over to the raid that sit there hoping a rebuild works.
As for complete systems. I prefer a reseller I trust to buy everything from firstly. If I was in the US Bob would be my first call to ask his preference.
S