German ram isn't good for new tank or new fish keepers. Five bar are awesome looking fish but highly aggressive. Almost all cichlids are aggressive you just have to know how to keep them and what you want to keep them with. Almost all my tanks have cichlids with very little aggression in the tank because of what I keep together.
First decide do you want a community or a solo "wet pet". With the tank size you have stated you are probably looking at a solo wet pet with some dithers (cheaper schooling fish) or small group of smaller dwarf cichlids. If you want a cichlid community you may want to go with a bigger tank. you
here are some suggestions google and let us know what you think.
Blue Acara
Electric Blue acara
Convict
Honduran Red point
Rainbow Cichlids
Firemouth
Bolivian Ram
