If you're sticking to the Vampire Aristocrats theme then the first cards I'd pick up would be Vampiric Tutor (finds Skullclamp and has Vampire in it!), Bloodletter of Aclazotz which doubles your drain / damage output on your turn absolutely wild, Bloodline Keeper provides sac fodder and a strong anthem, Legion's Landing nice thematic ramp, and Sorin, Imperious Bloodlord thematic ramp and removal
While the initial price explosion has happened, its unlikely to fall back to its old price
From here, Craterhoof Behemoth will do all the work, buffing all your creatures while also giving them Trample
Theyve been around since Alpha and show up regularly in most sets
Also, it makes it so that whenever you cast a Zombie spell, you get a 2/2 black Zombie token