Angelfish are definitely happy in pairs

I don't know much about cories so I can't help you with that. If you're seriously thinking about angelfish, make sure that everything that goes in with them is compatible with them. If you're getting angelfish that are still very young and small in size, you can get smaller fish with them such as neons and other tetras, or even some other small fish kinds. However, if you're getting fully grown angels, be careful with putting any smaller fishes with them. Angels have quite a personality. If they were not raised with small fish from babies, they may regard small fish as food. Their mouths are pretty large when they're grown, so they could easily eat smaller fish! I personally have 2 angelfish that have been raised with 12 neons from babies, so they are used to the neons and don't even bother with them.