What are you calling an Oscar like temperment. As I have found Oscars to large fairly mellow and always hungry. That would open the door to a lot of larger Cichlids. Any way you may want to look at the Synspilum or Red Head Cichlid. They have great color and will get along with smaaller fish.
lot of friendly fish out there, but nothing as interactive and friendly as a big ol lumbering Oscar. If I could only have one fish, it would be a big ol lumbering lutino Oscar. IMHO.
They are very similar to Oscars, personality-wise. They do seem to move around the tank a little less than an Oscar. Ours like to swim at the upper parts of the tank and look up, waiting for a bug to fall into the water.
I think the closest I have found is uaru amphiacanthoides. The standard uaru. When they are young, they are friendly and energetic. As they age they get much more mellow.