I would try Westwind (which used to be part of Pan Am a long, long time ago) across the parking lot from TransPac. There are also flight schools at Glendale, Scottsdale, and Williams Gateway which have occaisionally posted for CFIs. I would try one of those first.
If it were still Pan Am, I would say go for it. Now that it is TransPac, I would not touch it with a ten foot pole. In my opinion you would be risking your ticket with each student. Anyone in management who was of any worth or value to the place it once was has since left or been fired. I am sorry to say that the good old days of Pan Am have long since gone, in my opinion.