Def ocellaris, if a store doesnt list what species it is 99% of the time its an ocellaris. But ocellaris are cool in the sense each one has slightly different markings so they can be real unique and cool looking
I have 2 kels with 2 oscars. Just try to get them to grow at same rate. Gonna need some good tank size for these fish.
Even if the pbass accelerate and grow faster once the oscars are stout I wouldn't worry about them.
In fact I had more problems with oscars being aggressive to a degree with the bass.
Under stress the fish could show signs of aggression in cramped space.
Enough space... should be fine.