Debating between magicka and stamina dk right now for close ranged magic/melee feel. I noticed dragon leap has a magicka and phyiscal dps version now to.
You will likely use venomous claw, noxious breath, and perhaps igneous weapons (but that can be accomplished with potions) in end game PVE as a stam DK.
Stam DK will be a DW/Bow build based on ether a rapid strikes rotation or a full heavy attack weave, and the Magic DK will run double staff and use whip as their spammable with a bunch of magic DOTs. Both play at melee range. Stam DK can probably pull a touch more single target damage, but magic is far more survivable and has more utility in a raid setting, so they are far more common in the current meta.
Neither will use leap in PVE. Standard is still the go to for DKs in PVE regardless of spec as far as I know.
Also Flames of Oblivion. It costs magicka, but scales based on whichever you highest stat is. Decent single target damage and good to use if you aren't using much magicka for buffs.