So, that'd be about like this:
The prestige class Dirge Singer would require any neutral alignment, 3rd+ level Wizard (Necromancer) and 4th+ level Bard. (Yeah, I know, I lowered the Bard level requirement slightly.)
Ok, so maybe the undead familiar wasn't such a hot idea, but I think that without doubt Animate Dead needs to be on the class spell list. And, since Bard spells are already Charisma-based, maybe we should give the Dirge Singer the Extraordinary Ability to turn/rebuke undead up to HD equal to his charisma bonus/2 levels? [So, for an 18 cha, that's 4 HD at 1st, 8 HD at 3rd, 12 HD at 5th, and so on.]