I have been keeping fish for over 20 years and the people in these forums always surprise me with their education, experience, and stories.
Regardless of tank size remember the escape factor. I have rescued eels from the carpet on a couple of occasions over the years. I have not had them
That is a nice tank. I have a 135 with 2 oscars and a bichir and JD and others in it. They all get along well enough. The oscars are friends and sometimes
Sort of, except not aggressive towards other species.