I need some expert advice on a build I want to run coming back to Skyrim. I want to play as a death knight that is more closely based on D&D lore than WoW. I need to figure out what skill perks I should get. I thought of being a Breton for the natural resist, using a 2h sword, possibly becoming a vampire since death knights are undead, and using conjuration for raising only zombies. I'm not sure if I should go into destruction since there are shouts that cover many death knight abilities or go into illusion for fear spells.

I think you should become a vampire. Make you're race a Breton. Wear all Daedric (cause you're a death knight). Use fear spells and also use the invisible spell.

What about destruction spells?

Ice is a good destruction spell for vampires. Ive played a deathknight before and theyre alot if fun. I also used restoration but only to get the necromage perk.
-heavy armor
-two handed
-smithing
-conjuration
-rsstoration

Definately become a vampire and play evil evil evil. Also id recommend using rhe ritual stone as well. Nothing like raising a draugr army to fight for you.
Also you might wanna check out the skyrim blog website. You can find alot of killer ideas there.