If you are just going to level all the way to 50, start out with full thrust/duel wield rest envenom. Will turn you into a merc with poison. Groups will like that. If you want to hit the BGs, well... that's taking the long road if ya ask me. I would start an infil from 0, level with the above spec which will autotrain your stealth. At 50, respec to a more cookie cutter RR appropriate 5 spec. I can't tell you what that is, because your best spec will change every realm rank.