any of the fish you listed/inquired about would be ok in a mix & match. Do not add any parachromis,veja,tomocichla,theraps,amphilophus or nandopsis
1 oscar,1 dempsey,1 male convict,1 or 2 geos.,1 firemouth,1 texas if you really want to drop one then let it be the texas & 2 silver dollars. but i see no reason you should if you're getting all young fish to start.