Algae Grazing Tangs

[Werbo]

I have a 120 G tank. I have a yellow tang and really love that the fact it is always grazing on what little algae it can find on my rocks. It seems really natural to watch and is benefical in algae management.
My wife really loves Regal tangs but after researching it seems they are more carnivourous.
I want to add another tang from a different tang family. What other tangs are primarily algae grazers and constantly searching the rock for algae.