My tank is just slightly bigger than yours and would not do an Oscar in it due to the size they grow, I have seen them in 60g but singly, a good sized pair in a 60g really wouldn't be right. You could do so much more if you went for Sajicas, Keyhole, Rainbow, Salvini sized cichlids. I leave the Oscars to those lucky guys with monster tanks, a member on here Hukit is a wealth of knowledge on new world cichlids and I think he knows a lot about Oscars he might point you in the right direction with them or good sized cichlid stocking ideas.