I partially disagree with the people saying to go Sunsinger, primarily because of the exotics you've picked up already. It's true that in general Sunsinger is better for high-level PvE content, having that self-revive is game-changing for hard raids. If you are raid-focused then it might be good to go Sunsinger, as the revive perk is at the very end of the upgrade tree so it'll take you a while to get there. But Obsidian and Voidfang are two of the best warlock exotic armors, and you'll need Voidwalker to take advantage. Voidwalker is excellent for PvP and for PvE other than hard raids. With Obsidian you can become a nonstop super-bombing machine, which is one of the most fun ways to play the game.