all you can do is mix the fish you want and some will work with each other while others will not so eventually you will have to take out the fish that do not work and keep the ones that get along.
If you want to be different, instead of a regular Texas cichlid, get an Escondido Carpinitis if you can find one. They have much better coloration in my opinion. FishfarmUSA has a bunch on aquabid.com for cheap.
I THINK THE JAGUAR AND THE FESTAE WILL BE THE MEANEST AND BIGGEST IN YOUR TANK. MY JAG WAS SHY AT FIRST LIKE THE 1ST YEAR TILL HE STARTED PUTTING ON WEIGHT AND SIZE. NOW HES A BULLY AND RUNS ONLY WHEN MY OSCAR NIPS AT HIM.