Ignition switch barrel (lock cylinder) supplier

Can't find it now, but will (hopefully) need it before too long:
Does anyone know a supplier for ignition switch lock cylinders (barrels) coded
to the car? I have an NOS switch, no barrel, and nothing with the barrel in
it. Hate to be picky, but I'd like to have one coded to the car. Thought I'd
seen this service advertised somewhere.
Dan