whoops sorry about that, i was on about the tiger shovel nose, the most common out there.
a lima should do well in there but like your arowana question your going to have problems introducing new fish with your 2 oscars.
another smaller shovel nose is the spotted shovelnose- hemosorubin platyyichys, these are quite hard to come by and tend to cost aorund £60 it seems at the moment, thats for usually a 4" fish.