In addition to full-set dolls, Dolk (Dolk Station) has announced that the Ciel head and special outfit may now be purchased separately. The pre-order will close soon.
From the retailer:
We are happy to inform you that “Ciel Phantomhive” Dress (Erithacus Ver.) And the Head can now buy separately. We also offer Layaway for every orders. Please visit and shop now, it will be close this coming June 12, 2016.