forgive me, I missed that line. That's why I was cautioning you about the pleco bio-load.150 gallon? the tank will be arround 520 gallon.
When i look to some pictures on Google the hoplarchus psittacus is a really nice fish!
In a 528 gallon… go crazy I would definitely get a Psittacus, you could do an Oscar as well, many geophagus, heros. I would only avoid Mesoheros like Festae, as their aggression levels are beyond most other SA's. And crenicichla would be great, but would eat smaller fish.