Nice tank!!!!!!!!!!
I have been keeping oscars for 7 years. I would suggest a Jag (a jack or green terror MIGHT work but in MY expeiriance, are usually much more aggressive than oscars and can sometimes be too much for even a pair of oscars although with that size tank MIGHT work) and an assortment of tinfoils, balas, or silver dollars (3 total)these will keep motion in the tank and mabey even a couple gouramis. I am setting up a 150 that will house my 2 12"o's 1 10" jag 1 14" pleco, 2 4" tinfoils and eventually a senegal birchir(when it's big enough not to fit in their mouth) hope this helps.