Drupal out of the box allows you to create custom page.tp files per url, but it does not allow you to create them based on the given node type. Here is a little snippet of code I used to define a custom theme hook suggestion. It basically tells the theme layer to look for a page--[node-type].tpl.php file that matches the current the node type that is currently being viewed. There were several places online that stated it should be implemented in _process_page() but I was only able to get it to work in _preprocess_page().

Simply place this snippet in your themes template.php and replace 'themeName' with the name of your theme.

/**
 * Implementation  of template_preprocess_page().
 */

function themeName_preprocess_page(&$vars, $hook) {
  if (isset($vars['node'])) {
    // If the node type is "foo_bar" (<--machine name) the template suggestion will be "page--foo_bar.tpl.php".
    $vars['theme_hook_suggestions'][] = 'page__'. $vars['node']->type;
  }
}