My question is do you have plants in your tank?
I would add with what you got and slowly build it up, buy 3 fish at a time so it doesnt shock your tank. I wouldnt add angels unless you really want a pair. Now as angels go, you are not going to tell the difference in them and neither are the store shop keepers. You find that out when they are adults in your tank.
Now don't get everyone wrong here, a 55 is a nice tank and you can have a bunch of fish, just not large ones. But also, remember more fish you add or larger, the more water changes you will need to do.
So later tonight, sit back and think on what you really want here. Go to the shop and look around. There is no need to rush and take your time. Don't let any one bully you into fish you do not want. But atleast take some of our recommendations. I think if you took back your Gouramies and Rainbows, get a pair of small angels.
I know you wanted a fish to eat your smaller ones, well these guys will do it. I had a school of 25 Zebras in a 55 with 4 angels, i did water changes 2 times a week. But my Danios kept on disappearing. The Angels ate them. They would dart out of the Giant Sword plants I had in that tank and grab a Zebra.