There's a thread (
http://986forum.com/forums/showthread.php?t=9615&highlight=local+mechanic) that deals with finding good/reasonable indys by geographical locations. I checked and, unfortunately for you, there were no recommendations for Houston, though there were people who asked.
You might want to pm
97 Boxster and
wdlnds09, see if they found likely candidates. You could also pm
RandallNeighbour, who's had an older Boxster for years and also lives in that area.