Synspilum was the species I was looking at, If they are too aggressive can I doParatheraps and vieja are a genus, not a species, and whether or not the fish will work in a community, probably depends on the species. Heterospila is pretty friendly and a good community fish, some others like maculicauda or zonatus are very aggressive. Whether your tank is a 180 or a 250 may make a pretty big difference. I would probably not mix the ultra aggressive vieja with Oscars and sajica. One fish I kept in that genus which I found pretty passive was vieja regain. Though, some other members on this site have had different experiences. I believe the vieja would go better with the aggressive types I listed than with the more passive Oscars and small sajica, and would work better in the 250 than 180
sajica pair
2 oscar
3 redshoulder sevrums
3 sun cats
4-5 silver dollars/tinfoil barbs
1 fire eel
Sorry if I'm asking a lot of questions, Haven't had too much experience with SA/CA cichlids....