You did not say WHICH HP power supply you need the breakout boards for.
Most are the HP Common Slot but there are others, you can find some oddball HP power supplies out there that are not standard.
If it's the standard one then did you reach out to sidehack?
https://bitcointalk.org/index.php?action=profile;u=130792He makes them and can probably get you what you need.
https://bitcointalk.org/index.php?topic=940317.0-Dave