Any kind of Brustletooth Tang (Kole, Tomini, two Spot, etc) should work if you want a Tang. Getting a Yellow, as suggested above, is a bad idea. They need larger or you will likely have the same issue with stress.The Emperor and Powder Blue would not have worked with your tank. Much too small, which causes stress, which often leads to the results you got.
If you want an Angel, look at any of the Dwarfs (coral Beauty, Flame, etc) or even Pygmys (Flameback or Cherub).
I see the possibility of future issues with the eel and smaller fish that you have now. Those could end up being expensive snacks.