In the wild, neons are one of the angel's normal foods, so unless they are all introduced in the tank as babies, your neons will probably get eaten. I'm not sure if the shark would be okay with the angels either. How big is the tank?
A 55 gallon tank will be excellent size-wise for angelfish. And 2 of them would be best. If you want to keep angelfish with neons, get angelfish while they're still small, so that they grow up with neons and get used to them. If you get adult angels that have never before been in one tank with smaller species, they may eat the neons.
I also am not sure if a red-tailed shark is OK to be kept with angels. I personally would NOT keep angels with this shark. Also, a red-tailed shark should be kept singly, as it will be aggressive toward its own species. Generally, it's not a 100% peaceful fish.