USB PCI cards are very cheap, less thn $40. Put that in your AIO and get a USB scanner. The combination of those 2 should still be less than a SCSI scanner anyway. Plus the USB scanner will then transfer to your new machine easily.
DB-25 means a 25 pin connecter, HDI-30 is a 30 pin connector. The PowerBook connector is more like a square, 5 pins by 6 pins. The AIO is 2 rows of 12 and 13 pins. For the PowerBook, you'd need to buy an adapter to get it to a DB-25 so the scanner's cable will connect.