I played a main Necro for years and had maxed AA's through Rain of Fear. I don't see how a Paladin partner does much for you? A Beastlord, Mage, or Shaman are all pretty good duo partners... but I always felt the Necro did the heavy lifting.
If you want a tank, then why not: Shaman (Troll) & Shadow Knight (Ogre)
-Legit heals
-Haste & buffs to all stats/resists
-SoW
-DoTs & Debuffs up the wazzo
-Slows
-Snares, Fears, Roots
-Pulls with high HP & AC, Feign Death'er
-Damage Shields
-Maybe a bit light on DPS
Or a Druid & Paladin combo, but you lack haste & slows which have always felt like a pretty big deal to me.