It should work with any Adaptec SCSI card of recent vintage. I have a Duoscan 1200 and a Duoscan running on two different machines with two different Adaptec cards.

I wouldn't trust any kind of SCSI/USB or SCSI/parallel converter to work consistently.

As to the kind of connector you'll need, that depends on the card. The scanner has a 50-pin Centronics port and a DB25 port. The SCSI card could have either of those or a compact 50-pin connection or a compact 68-pin connection, if it's a relatively new Type III card. External SCSI ports are always female, and the cables are always male at both ends, if I'm not mistaken.

Also, I hope you made sure the card works with your computer. Most new computers have only PCI slots, but older SCSI cards could require an ISA slot.