How to redirect to another page after submitting the ctools modal form
This is a bit old, but hopefully it'll help someone. Down where you write your commands[] array. Change it to something like this. In the submit function of one of the earlier forms I set the redirectpath parameter on the object, then i just use that in ctools_ajax_command_redirect() after calling the dismiss modal function ctools_modal_command_dismiss().

  // If $output is FALSE, there was no actual form.
  $commands = array();
  if ($output === FALSE || !empty($form_state['complete'])) {
    // Dismiss the modal.
    $finish = _aap_main_add_finish($form_state['object']);
    $commands[] = ctools_modal_command_dismiss();
    ctools_add_js('ajax-responder');
    $commands[] = ajax_command_html('#ctools-sample', $finish);
    $commands[] = ctools_modal_command_dismiss();
    $commands[] = ctools_ajax_command_redirect($form_state['object']-&gt;redirectpath);
  }
  else if (!empty($form_state['cancel'])) {
    // If cancelling, return to the activity.
    $commands[] = ctools_modal_command_dismiss();
  }
  else {
    $commands = ctools_modal_form_render($form_state, $output);
  }