Finding a scsi card shouldn't be hard, the bigger issue will be drivers or both the card and scanner.
I have the drivers for the scanner. I thought I had my problem licked when I bought a USB-SCSI cable from Adaptec. My Nikon is an LS1000, come to find out, the oldest one they support with that cable is the LS2000. This was 3 years ago when I first bought my Dell.. Now I'm into an HP computer and with the same scsi problem. I'm not completely without it though. I do have the old setup on an older computer, it's just a PAINFULLY slow process, about 2 minutes per slide.. I'll get it...
I've been playing with the idea of adapting a slide copier attachment to the FZ20. If it can do macros of a bug, why not a back-lit photo?? Might work for my Medium format stuff too :-)