I haven't set a name yet, despite the game nagging me every time I login.
I was originally going to pick ", Sith'ari", assuming the comma is allowed, but the more I thought about it as I neared level 30, the less it would fit with other characters. A Bounty Hunter is not a Sith'ari per say, especially if she is Chiss. ((see my character bios)) I suppose it could work if I kept her bio as is or simply go by the definition of Sith'ari. An overlord Bounty Hunter who won the Great Hunt could make sense... It would work fine for an inquisitor, but then there's the same sticky situation of explaining how an imperial agent can be a Sith'ari.
Also, do the legacy names carry over to republic characters? Would be funny to run around as a level 1 trooper with the surname of Sith'ari.