Wardens didnt get a house themed off them (sweet Azura I wouldve thrown money at that so fast) so why should Necros?
Yeah, that's pretty much it I think. If you make a dunmer, orc, or a breton necro you could easily get away with using Daggerfall Overlook, Forsaken Stronghold, Velothi Reverie, or the Ebonheart Chateau as well, the dark stone interior of those can have a proper evil vibe if furnished and lit appropriately.The closest I think right now is Erstwhile Cavern for a necro home.