Hey! Sorry I didnt respond sooner!
Angels can be rather finicky about water conditions and will do better in a larger tank so you should abstain. However if you do get them, don't get the gouramis because they like to both control the top of the tank. If you do get smaller angels, make sure your parameters are nice and stable and get them as babies.
Since you have a 50 gallon, I would get multiple dwarf gouramis and provide a lot of hiding places. When you get dwarfs them, try to get 1 male and the rest female and this will keep aggression to a minimum. I'm not sure what you look for in your gourami's, but a good gourami to have is the sparkling gourami. They like to be kept in a harem so 1 male to 3 females. So theoretically you could have 2 males and 6 females and be safe. They are rather peaceful when it comes to gourami's, and look very nice imo
Hope I helped, - Raymond