I'm sure that power cable has the power supply for the EL wire embedded in the plug housing.

Really, if you want to make a SCSI cable like that there's nothing stopping you, assuming you can find or make a 20-something conductor cable with a clear outer insulation you can thread the EL wire into. I'm just skeptical that driving the inverter with termpower is a great idea. There are plenty of other places you can tap 5v or 12v in a chain of SCSI enclosures.