Well, as far as quality undead minions, you could always take some intelligent creature then use the MM vampire template then use the DMG's toolbox to give them class levels. I am fixing to unleash an army of centaur fighter/ eldrich knights on my unsuspecting PCs cities in a current campaign. Dont worry about HD control rules. You could always make some item that controls undead to put in your bad guy's inventory. The magic item tables are a guideline, not a straight jacket unless your campaign is some kind of lame "official" sanctioned deal made to sell modules. Or who knows, the vampires may just think your bad guy leader is just an awesome dude.
Of course, scale and include mooks appropriate to the campaign's power level. I doubt a vampiric duo of level 20 Tarrasque oathbreaker paladins is cool for a level 10 campaign. Then again, it WOULD make for an interesting end campaign threat in the background. /evil grin.