12inch pleco(already with tank)
rtbs(already with tank)
angelfish
congo tetras
discus
cories
danios
bala shark
pearl/golden/blue gourami
Okay, using the fish you wanted, here is my suggested opinion:
5 Angelfish -- A group will look better, I suggest you either get all one type or all different types. Not just like 2 of one kind, 2 of another and one other kind. But that's just me.
12 Congo Tetras -- These fish tend to look nicer in large groups
3 Pearl Gouramis -- These fish may become a little skittish but I think they'll be okay, especially if you have three.
That might leave you a little bit overstocked, but as long as you have good filtration you should be okay. Also, one thing you could change is switch out the pearl gouramis with the RTS, I just think the Pearl's colors would look better with the other fish I suggested. It kind of depends on what sort of angels you get though.