I also live in Dallas and have to say that I am shocked that you found any epis in any of our area nurseries. I did get a night bloomer once, assume it's an oxypetallum (sp too funny). It had literally just come off the truck from Austin and the nursery had no idea what it was. In fact I now have 2 buds on it.
I am a plant abuser but if you would like to discuss with me growing epis in Dallas, just shoot me a private message. (I'm new & assuming that we can do private msgs.) I would love to give you cuttings and more. Like the tea party in Alice in Wonderland, 'No room, no room!'