I'd ditch the Oscars and go with a GT, a Blood Red Jewel and a Salvini. Then you can do a pleco/udc and some silver dollars or a few scavengers.
If you're keeping cichlids, I'd strongly suggest more mechanical filtration than what I saw listed. They are messy fish.
If you're keeping cichlids, I'd strongly suggest more mechanical filtration than what I saw listed. They are messy fish.