don't do it. many of the large angels, especially emperors, are known for being very sickly, especially when they are juveniles. it will be far too big. if you spend that kind of money on a fish only to have it die, you'll probably be very discouraged very quickly.
many of the dwarf angels are as beautiful as their big cousins. I have a coral beauty. I like the flame angels a lot, and there a lot of other nice ones.
if you get a large angel (even at juvenile age), I believe you'll be disappointed. I never had a real grasp of how big they are until I went to a public aquarium. they had a French and a Gray that were each about 2 feet long and one foot from top to bottom. that's a big fish, even for a large aquarium.