A bit in the dark here.
You haven't given any detail or name of the Scanner or the host card. Wherever you buy, you could help yourself by looking up the scanner on the maker's website for as much info. as you can find before you go tho the retail side of things.
Assuming that it is an oldish scanner then almost any PCI to SCSI card will do and the cable must obviously fit both the scanner and the card which you choose.
I have an old but very reliable SCSI scanner with a large 50 pin socket on it, while at the computer end it has what I believe is called a 50 pin Micro-D socket.