Angels are generally compatable with tangs and clowns, and, like tangs, they are grazers, thus they will appreciate your providing extra veggies on a lettuce clip. What you need to do is think about the size of your tank when considering what angel to get. Some angels get very large, thus, if you have a small set up, a large angel won't be very comfortable. The pygmies would be a good choice and they do very well with tangs.