Since fire eels natural range is India and Sri Lanka to Viet Nam (and because I like my display tanks to be geographically correct) I would choose fish from those areas.
Some of the larger gouramis or barbs would be correct.
I believe a 220 is too small for peacock bass, but for a geographically correct cichid, a shoal of Etroplus suratensus (endemic to Sri Lanka and India) would work well. The are too large as adults for be considered food for the ells, and non-aggressive, so not a problem.

they get to be the size of dinner plates

Some of the larger gouramis or barbs would be correct.
I believe a 220 is too small for peacock bass, but for a geographically correct cichid, a shoal of Etroplus suratensus (endemic to Sri Lanka and India) would work well. The are too large as adults for be considered food for the ells, and non-aggressive, so not a problem.

they get to be the size of dinner plates

