Dwarf Gouramis with platys and/or guppies maybe with some corys. Mollys maybe or even swordtails. You could have a big school as an option. Swordtails can reach 4.7 inches so that should be big. Just be warned that if you have livebearers like swordtails,platys,guppies,mollies, and some other livebearers you will have lots of fry unless you keep only one gender.