Khanate irritate me, and not in a good way. Their debut was one of the few CDs I have ever payed money for that ended up as frisbee material. Their gimmick is interesting... for one song.
As for doom... start with traditional stuff like the Candlemass debut (all candlemass records are awe, but their debut is special ) St.Vitus (born too late) Trouble (Psalm 9, even The Skull) Pentagram (not the Turkish fellows). Then go for the romantic doom/death stuff like MDB (I trust you have whatever you need from the MDB catalogue but I'm mentioning them just in case) Mourning Beloveth, Saturnus, Evernus. Evoken are great. Morgion's 'Solinari' is excellent if not a bit thin on the guitar production. I second Skepticism. dISEMBOWELMENT are excellent. Winter, Unholy, Deinonychus also are ok. Get 'Times of Grace' by the band Neurosis also, since it's the most doomy non-doom album I've ever heard. Thergothon are a good bet in funeral doom, also.