Iguess noone really knows to that answer. I came across one called Tutti Fruitti. It might work...

I was told by a local nurseyman that, here in north Florida, the indicas, like formosa, had the best chance of surviving in full sun. The theory was that the bigger azaleas can produce their own shade, which can help to prevent their roots from drying out.

Evergreen azaleas, even in my mild PNW summer sun, simply do not care for a full sun location. While they will live and even thrive for a period of time, deterioration is inevitable. I can't imagine too many hybrids, regardless of parentage, doing very well for any length of time in full-on afternoon sun in Texas. You might consider deciduous azaleas - they are far more sun tolerant than the evergreen species or hybrids and actually prefer considerable sun to shade, plus have the bonus as being less mildew prone in this situation.