Hi Sasha
When planning an aquarium, it's a good idea to think about getting fish who will reside at the top, middle and bottom levels.
Gouramis, which are air breathers live primarily at the top. Pearls are an excellent choice, but so are any of the others. The pictures you see of them never do them justice. But, if you have angels, they will chase and nip at the gouramis.
Gouramis are territorial fish, but are only a problem with other gouramis. Do not over stock them and you will be fine. I have never had trouble with gouramis behavior toward other species.
For the middle of the tank, a school of small fish is nice. I like glowlight tetras, but there are many interesting schooling fish available. You will probably want to choose an active one. Another choice is the glass catfish who will find a spot among the plants and pretty much stay put. Here's a link about these unusual fish:
http/www.aquariumfish.com/aquariumfish/B...d=6244&cid=3680
To add interest and activity to the bottom level, IMHO, nothing beats a school of corydoras. They are good community tank citizens who get along with everyone and are seldom bothered by other fish. Here's a link that will show you the many varities:
http/www.planetcatfish.com/catelog/calli...ra/g_thumbs.htm
I've kept all these fish in my community tank with good results.