Not all 'convicts' are the same. The term 'convict' is used to described any of the several species within the genus, Amatitlania. They vary greatly in aggression from species to species so I'd recommend you seek out some Amatitlania siquia and try to avoid Amatitlania nigrofasciatus or kanna. Within the species 'siquia' there are several striking variants to pick from, few of which get as big or aggressive as nigrofasciatus. Amatitlania siquia 'Honduran Red Point' would work well for you.
Alternatively, you could go with any of the Archocentrus or Cryptoheros species which are closely related.
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