It'll be perfect for angels. I had six mated pairs in a 75 for about four years. Started with 14 small quarter-sized angels and gave away two once the rest paired up. They all laid eggs about every two weeks. When a pair is guarding eggs, wigglers or the last free-swimming fry that haven't been eaten the rest of the fish are kept out of their territory. If things get too nasty you just pull out the leaf with the eggs and everybody is happy. (be prepared to be bitten though) They'll never be able to raise their fry unless you pull out a pair and give them their own tank. Now that's an amazing thing to watch. I used to give the babies to a local shop most of the time.
One thing that was cool about that tank is that even when nobody had eggs I always knew where in the tank each pair would be. They each had their own area in the tank.
For me it was fine until one morning my favorite black angel was dead for no obvious reason. I didn't get his mate out of the tank and the rest picked on her mercilessly. By the time I put her in another tank it was too late to save her. So that's something to watch for.
If I were you I'd start out with six or eight as long as you've got a mom n pop shop near you. Most will take a healthy angel.
Malaysian Trumpet Snails: JUST SAY NO!