It may be a long shot, but I have a Tempo SATA X4i that I wouldn't mind parting with. Despite being a PCI-X card, it says all over the box it will work in PCI-X and PCI slots. I guess the unused pins would just hang off the back of a PCI slot? The chipset is a Marvell 88SX.

I paid quite a bit for this a while back, but I would be willing to take a hit on it as I no longer have a need for it.