I have the Logitech hand scanner for the Mac.  It uses a SCSI
interface box that the standard scanner unit plugs into.  I
have tried my friend's IBM hand scanner with the scsi box and
it works.  See if you can get Logitech to sell you the scsi
box by itself.  Warning:  most of the cost of Mac handscanners
is contained in the scsi interface box, so it could run up
to around $200.  When I upgraded my old style scanner to
the new gray scale model, it cost $75; they just gave me a new
scan head and software; the box was the same.  The gray scale
scanner + interface runs about $300; making it around $200 for
the interface.