How do I make a page-specific .tpl?
With theme hook suggestions:

function MYMODULE_preprocess_page(&amp;$vars) {
  if (some_contextual_condition()) {
    $vars['theme_hook_suggestions'][] = 'page__about_us_gallery';
  }
}


The above will correspond to a template file in your theme named page--about-us-gallery.tpl.php