On that note there's absolutely nothing wrong with keeping a flowerhorn, but like maddyfish stated, you likely won't be able to do it with two oscars. I would say the bare minimum for two Oscars would be 90 gallons, preferably 120 + . What size tank have you got?Long run a Flowerhorn will be too aggressive for your Oscars unless your tank is 500 gallon plus. On that note for 2 oscars you'll need around 120-125 gallons.
Do consider buying a real fish instead of a hybrid creature as well.
^^good pointI'm not sure an adult male FH would accept 2 oscars even in a 180. For a flowerhorn to accept the oscars you'd probably have to move up to the custom tank range 300+ gallons.
Maybe a female FH might accept oscars in a regular home sized aquarium.
My RD considers his 4 ft tank his, plus several feet to each side, and about a foot out in front of the tank. He would not accept an oscar, a dog, a cat, or a person for that matter in that space.