29 gal?.......How about a pair of HRPs? Or a pair of rainbow cichlids?.....OR.....Raise up juvi EBJDs until they get about 3", then sell them for $$$$$$$.....Just a couple of suggestions.
MIKE
55 g is too small for an Oscar. They get 12"-15" and they're built like tanks. Just because people put an Oscar in a 55 g doesn't mean it's the responsible thing to do. They're just too big for a 48" x 12" tank. I saw someone's suggestion for a Firemouth and that's an excellent idea. Personality Plus and he'd stay small enough for a 29 g.
By the way-Oscar's aren't 'aggressive', they're more territorial. A Firemouth is more "aggressive" than an Oscar.