There are tons of cichlids you could put in your tank (provided you get rid of the texas and oscar, which as already stated are way to large for that tank). Rainbows, cupid, kribs, rams, shellies, brichardi, smaller geophagus, convicts etc. etc. Reaserch a little and you will find lots of info right on this forum.
PS If your LFS told you those fish would be okay in your tank I would tell them they are idiots and never shop there again.