Hey Juan! Nice to see you back on board!
I don't think I would ever even attempt to put my FM's with my angels. I did have a very small Severum wih them for a while with success, but it was never intended to be a permenant situation either. (Just until he was big enough to go with my other big fishies!)
Also, Juan asked a very important question, how many angels and gouramis are already in that 30g tank? With cichlids, including angels being as territorial as they are, adding a more aggressive and teritorial fish to the mix could be a recipe for disaster. With angels, I believe in a 30g tall, no more than 3 angels are recommended. Basically, you figure about 10g per angel.
Good luck!