Is drana or olivia voldaren better as commander ? I have tons of vampires mostly black though just wondering which direction I should go for and also a basic build idea , I have looked at several can't seem to decide

Olivia is why better in my opinion. You get access to reds burn effects as well as awesome creatures. Falkenrath Aristocrat, Falkenrath Exterminator, Crossway Vampire, Markov Warlord, Stromkirk Captain, Stromkirk Noble, Vampiric Dragon are all great Vampire creatures you can be running.

Valdor is right. Olivia, Stromkirk Captain, and Falkenrath Aristocrat make a huuuuuge difference. Keep in mind that the deck with Olivia will need to be a bit more aggressive than your typical edh build. I had one not that long ago (viewable here: https://deckbox.org/sets/566639) that was actually some good fun. But keep in mind that Olivia will draw some ire from most groups once you steal the first opposing commander ;)