I've wanted a flame angel from the get go but we went with other suggestions... that didn't work out.
Both were in the same tank at the lfs
and were introduced to our tank at the same time. It's interesting to watch the two interact. The flame causally swims around, in and out of rocks, and the tang can't stand being alone OR is establishing his dominance (he follows the flame every where). I have seen no real aggression yet though.
The clown has nipped the the angel once that we know of but that was on day one.
What a blast to watch... I could sit there stairing at the tank all day