There's the Corpse Creature and Bone Creature templates that keep their Class Levels and are created with Create (Greater) Undead. Better than Awakening them.

Necrosis Carnex to keep around and heal your troops

Summon Undead IV-V is amazing, as it gives you control of an Allip; Few things are imune to Wisdom Drain.

Animate Dead to have Dragon Zombies. Potentially a Giant Zombie too.

Finally, I advise against Multiclassing. Anything that harms your Caster Level is by default not worth the trade. Exception in some PrCs, but that's not the point. Clerics are the Best Necromancers, but if you want something fancy, you can always go Dread Necro safely.