Your printer and card reader connect to the USB ports. They are a standard size.
The pins the ebay seller is talking about are the size of Firewire port. You may not even have one on your PC, that's why you can't find them and are getting mixed up with USB.
Firewire is a better way of transferring DV footage to a computer so you can fit one in a spare PCI slot fi you want to do this regularly. Have a look here
-------------------- OK OK I can't go any faster! aaaaaaaaaaaagh!