Help With Kazakus Priest Decklists

Hey, I'm looking for some help with what cards to use in my Kazakus priest deck. I've got most of the cards for a KoFT Kazakus-Quest-DK Priest deck, but I'm missing some of the more Tech-y neutral legendaries.

I have a lot of dust and was wondering what legendaries would be the best to spend it on. Right now I have N'Zoth, Elise the Trailblazer, Kazakus, and Medivh. Some legendaries I've seen in many decks and seem good for this deck include:

• Cairne Bloodhoof
• Arfus
• Bloodmage Thalnos
• Lich King
• Barnes

How do you guys feel about these cards. Which are really necessary, which are not very good. Are there any other legendaries not listed I should look into? Thanks for the help!