kissing gouramis get to be around 12 inches long and are pretty aggressive with one another. minimum of 125 gallons for two IMO with PLENTY of plants. maybe even a wall of plants so they cannot see each other to prevent scuffles.
a 20 gallon is to small for angels too, they really need a 29 gallon or more for the height and space.
i agree
its a nice tank, though more suitable for a few livebearers, or a ram community