First, I believe commonly known as a leapord, the second I've got one simliar to, its sorta what a wild angelfish looks like... I can't think of the name sorry, I'm kinda tired.
They are nice angels, I don't know what type they are though as I am still a newbie.
$4 is so cheap for an angel, here in west oz we pay $10 for a small angel and up to $40 for a larger angel.
Second pic seems to be a half black silver. Can't tell by the first pic what the back half of the fish looks like. You can find some interesting articles on genetics that may help explain your fish at http/theangelfishsociety.org/genetics.htm
I am not really good with these things but it seems their names often simply come from their patterns/colouring. Like black angels, koi angels and there's also altumn.
Those ones are very nice looking, worth $4 of anyone's money.