I came across a website for a guy that made cables but there hasn't been any activity on his site since 2009 so I figured he was more or less out of business.

I didn't think it would be too difficult to take one of those 4 pin cables that has 2 +12V wires and make it into a single +24V line. People that have checked those +25V lines say they are actually +24V so I don't think it would be an issue.