I do not know what do you mean by convict parrot cichlids, do you mean by convict cichlids and parrot cichlids? I used to have them at home, i bought my convict for less than 3 months and i bought the parrot cichlid not even an hour ago. If you were talking about blood parrot cichlid, they are very beautiful in color but their vertical mouth makes you hard to feed. Convicts are very cute, when i bought them they were shy hiding in a boat, but now when i approach my tank, its even more active than my flowerhorn, always swimming toward me on the water surface begging me for pellets. Convicts are hardier than most cichlids and breeds every 4-6 if you have a pair, i bought a male and female and they were not a pair; however, the female convict(always have orange spots on its belly) bred once a week after i had it.
Koi angelfish fish is another confusion to me, do you mean koi and angelfish? Angelfish are hardier fish because its a type of cichlid, can be kept with convict due to similar size, but koi is cold water fish, and is not good looking.
Gourami is like livebearers, they died so easily and very sensitive to new water condition, mine died within 5 days.
Zebra danios is another small and non-aggressive fish which is boring to watch.
Tomorrow i am going to buy a jardini arowana(Semi-aggressive) to introduce to my 29 gallons tank, but it do best in 90/+ gallons tank, may you can try it out too, i heard you can tame it. You can also try severum or discus, these are all semi-aggressive, beautiful and expensive fishes to keep.