Where are you trying to put the Sleeper and his Wardens? Alot of models are zone specific, and those are certainly one of them. You can modify what models each zone can have, but then the memory requirements for each zone can be so much they will crash (if you put in too many models).
I remember I wanted to add Lord Mithaniel Marr and Rallos Zek to some newbie zones, so I could take the shape of one of them and terrorize newbies on my server. Unfortunaetly I found out that I couldnt do that (I was too lazy at the time to bother adding them to other zones), so I was limited to terrorizing people with those models in the Temple of Marr, and Drunder.
Check this guide out: EQEmu Server Guidebook v1.2. I believe somewhere in there is the method to adding them. Just look for the link in the Tutorials and Howtos section.
Edit: NM with the info being in the guide (although the guide is still extremely helpful, and among other things, shows what models go where, and what gender they are) Go to this thread and try this method:
http://www.eqemulator.net/forums/vie...=adding+models