The problem I have learned with big fish in small tanks is the amount of work involved to keep the conditions healthy. Where as if you go small you can get other small fish along with it to have more activity and more enjoyable since your not doing water changes every day.
I would go with one of the smaller Convict cousins Honduran Red Points or Nanolutea. Add in 6 or so live barers like Plattys, Molly's a single hoplo catfish or busynose pleco.
Or you could do an African version with Jewel cichlids, Congo tetras or African Red eyed tetras and a smaller Synadonis catfish.
I would go with one of the smaller Convict cousins Honduran Red Points or Nanolutea. Add in 6 or so live barers like Plattys, Molly's a single hoplo catfish or busynose pleco.
Or you could do an African version with Jewel cichlids, Congo tetras or African Red eyed tetras and a smaller Synadonis catfish.