The tried and true down here south of Houston is
Graptopetalum paraguayense, Ghost Plant
Ghost Plant (XGraptosedum 'Ghosty')
It's a pass-along, so any gardener in the area should have a chunk to spare. A single leaf will start a new plant even. It will take full sun, part sun, no sun... and it's pretty hardy even in containers although it might die back when there's a ghastly freeze like we had a couple of winters ago.
A lot of the lovely Sedums, Escheverias, etc. just melt away in our combo heat and humidity.
