You could do a shoal of Pink-Tailed Chalceus (Chalceus macrolepidotus). They get upwards of 10" and stay predominantly at the surface.
Check out their profile here: http://www.seriouslyfish.com/profile.php?genus=Chalceus&species=macrolepidotus&id=162
Check out their profile here: http://www.seriouslyfish.com/profile.php?genus=Chalceus&species=macrolepidotus&id=162