2 oscars need 55gal's of space bare minimum. You could do it, but it would not be a wise thing to do. Your looking at 2 12in+ fish in a 1-1.5yrs time. Trust me I've owned 2 big 14in oscars I kept in lone 75's one will fill that space up within a yr or so easy.
What I would recommend would be 1 of the following: severum, male convict, male firemouth, or if your into cats a featherfin syno. This will be much better for water quality and swimming space.