You might be able to do firemouths and convicts.
If you can get access to more rare species like any other Archocentrus stay small or even a female green terror would work with a community.
You could have some geophagus in there with some severums.
You could probably have severums with almost anything they are nice and docile (for a jumbo cichlid!), but can still hold their own. If you want you could do all severums and maybe put about 5 in there to keep the aggression down in case you got a mix of male and females.
There are a ton of possibilities, but it just depends on your resources (aka fish store supply), you money, and of course your personal preference.