In my experience angels and gourami's don't do well in same sex pairs (unless they are in a very large tank of 150g or more).... sometimes not well in opposite sex pairs if they aren't compatible with each other. Then there's the question if you want them to breed or not? If you don't want fry I'd stick to one male of each.
I meant to put 6 GBR. If you want a school of GBR there's different opinions as to what works or not.....some say 2 females to 1 male, some say 1 female to 1 male, some say all male or all female. I think it's going to depend on the specific GBRs you get. Some think all males will be aggressive since they will all try to establish territory and some have not had this problem. In a tank your size I think they would have adequate room for territory. Some who pair of males and females find that some don't pair off and get bullied by the ones paired off resulting in having to remove the odd ones out of the tank. Then some don't have that problem. A good person to talk to about GBRs is a member called Coralbandit. He raises them. You could always add 6 GBRs of whatever sex you decide and see what happens and remove any who are being bullied. Essentially, you may have to experiment with it.
As far as order I would add your peaceful schooling fish and bottom dwellers first. Then add the GBRs to establish territory. Then add your Angel and Gourami last. If your adding them as all juveniles...which I assume you will...and they grow up together I feel this lowers aggression amongst each other. Although, temperament can change into adulthood.
