I 'm a tinter in Seattle and i would just call up some shops and ask questions, like do you shave the edges? do you warranty you work? what kind of film do you use? I'd stay away for Llumar, and Suntek, they are pretty low quailty films. They may have a lifetime warranty but optically they look grainy. Johnsons and 3m are good. Madico is the best all around, its very optically clear, lasts forever, and has a great hardcoat to prevent scratching.
I ve been tinting for over 10 years and used most all of the tints made, madico is the shit, period.