There are a lot of enquiries on Ciel and Sebastian and I thought it will be good to jot them here and for some quick references.

Ciel and Sebastian are both Ball-Jointed Dolls (BJDs). For a quick explanation of what a BJD is, here is the Wikipedia's explanation:

"A ball-jointed doll is any doll that is articulated with ball and socket joints. BJD style has been described as both realistic and influenced by anime. They commonly range in size from about 60 centimetres (24 in) for the larger dolls, 40 cm (16 in) for the mini dolls, and all the way down to 10 cm (4 in) or so for the tiniest of the tiny BJDs. BJDs are primarily intended for adult collectors and customizers. They are made to be easy to customize, by painting, changing the eyes and wig, and so forth."

These BJD doesn't come with makeup, outfits, eyes , wig. The price quoted for these dolls is usually just the basic doll (head+body). To cut long story short, I have appended some information about them:

Ciel Phantomhive - The Doll
Doll Company : LUTS
Country of Origin : Korea
Doll Size : 43 cm, Kid Delf (so-called MSD size)
Mold : Bory
Gender : Male
Skin Tone : Real Skin Normal
Price : US$ 240 (correct as at journal)
Limited Doll? : No
Modding Required? : No
Makeup opt available?: Yes
Link : [link]

Ciel Phantomhive - The Accessories
Clothes : The set of demon outfit is made by me
Shoes : LUTS.
Wig : Bought from someone at a event
Eyes : [link]

Sebastian Michealis - The Doll
Doll Company : Immortality of Soul (IOS)
Country of Origin : Korea
Doll Size : 62 cm (so-called SD size)
Mold : Blood
Gender : Male (Demon ^^)
Skin Tone : Normal Skin
Price : US$ 470
Limited Doll? : Yes (offered for a period of time)
Modding Required? : Yes
Makeup opt available?: No
Link : [link]

Sebastian Michealis - The Accessories
Clothes : [link] or at IOS.
Shoes :
For Osiris, I highly recommend this [link]
For Blood, I had this [link]
Wig : Self- customise
Eyes : The normal red acrylic eyes. Available in most doll websites.