Actually, in the timeline of Sith History...'Darth' Names (Darth Vader, Darth Maul, etc.) were not used until 2000 years before the Galactic Civil War (which took place during Star wars IV-VI) and were created by the only remaining Sith after the attempted rebirth of a Golden Age of the Sith - Bane, who became Darth Bane. It was at that point in time that he decided the Sith would no longer be a Dark Lord with followers but would be a Master, an Apprentice and no more therefore leading to the secrecy of the Sith and the supposition that they had vanished. Therefore, when the Sith were still as they were with a huge band of followers and a Dark Lord - 'Darth' was not a title given to any Sith lords. This is a mistake in the Original KOTOR and will hopefully be rectified....but as far as the story goes, no I don't belive you should be given a sith name. Also, as far as Darth Gandalf's point - that's the reason they did not change their names, because they would have never been "Darth's" to begin with. In the Trilogic timeline (Both of them) Names are changed for secrecy's sake such as Anakin Skywalker (Darth Vader), Senator Palpatine (Darth Sidious), and Khameir Sarin (Darth Maul).
