Fish Recommendation

[Fawah40]

Yes another one of these posts, I worked hard to get what I have happy/healthy and don't want to mess it up.
What I have:
#
20 US gallon tank:
6 Skirt Tetra
2 Mickey Mouse Platy
2 mystery snails
1 Oplina Gourami
1 Bamboo shrimp
3 Fava Ferns and a moss ball (want to get maybe some fava moss/more easy to care for plants, will take recommendations on those too).
Test strips (yes will get better test equip when strips run out )
Nitrite 0
Nitrate between 0-20
Hardness 150 (well water)
chlorine (NA, well water)
alk 120
PH 7.2-7.8 (closer to 7.8)
#
My wife wants some colorful fish, I wouldn't mind it either but not at the expensive of over stocking.
Any recommendations?

 

[Rex740]

Killifish possibly. Or you can add colorful types of platies such as variatus or perhaps even a swordtail or two.

 

[karin]

With that size tank, another school of tetra? Cardinals? Neons?

 

[Carlovel1]

Sorry but that tank already seems overstocked.The gourami needs a much bigger tank.

 

[Fawah40]

Sorry but that tank already seems overstocked.The gourami needs a much bigger tank.

Really? I only have 9 fish, but again if what I have should be all that I should have until I get a bigger tank then so be it. My Gourami is about 2 inches right now, how big do they get (LFS said ~4 inches).