preditory fish means that it will eat smaller fish
go with
bichir , african brown knife , leapard bush fish , mabye a buterfly fish and a catfish
south american leaf fish stay small so avoid those so do the butterfly fish they might get eaten depends on the bichir and catfish if you get one but a leapard bush fish or ctentopoma ? or how ever you spell it forgot last part to but its a ctentopoma species they get around 6'' and are cool , tuff and preditory
shovel nose get way to big unless its a lima shovelnose but that to might out grow your tank or atleast eat your other fish
salvini cichlids are proubly way to aggressive so are most cichlids that are preditory but if you wan't a sa/ca cichlid then go with an acara species