[Jacobite]

From what I know of the Souls Drinkers I say Loyalist. I havn't read the books so I'm not sure on this but the general rule I use with that sort of thing is "Do they use deamons?"

- Yes: Codex CSM
- No: Codex SM

Simple and easy.

 

[Jacobite]

They were in WD a while ago - like early 2003-2003. They may be on the Internet somewhere or try the Index Astartes books.