Open a modal form-dialog at AJAX callback

Essantially what I'm trying to do is to open a modal dialog (containing another form) during an AJAX form-callback. So far I know that I can bring up modal dialogs by using

- a link (class: "ctools-use-modal")
- a form that holds a button and a hidden url element

In my case I need to be able to open a form (in a modal dialog) dependant on user input e.g the result of a select-list-element.

I see basically two ways of accomplishing this:

1. Put an AJAX-callback to the select-list that changes the hidden url-field -> open the modal with a button. This worked BUT when I close the modal dialog the select list's ajax callback won't get triggered anymore (so it only works the first time).

2. Leave the button out and open the modal at the select lists's AJAX-callback directly. This also works BUT the modal-forms submit callback gets ignored.

Does anyone have an idea to solve this? Here's my example code (version 2):

/**
 * Implementation of hook_menu()
 */
function ajax_madness_menu() {
    $items = array();   
    $items['ajax-madness/dependant-modal'] = array(
        'title' => t("dependant modal"),
        'page callback' => 'ajax_madness_dependant_modal_page',     
        'access callback' => true,      
        'type' => MENU_CALLBACK,        
    );          
    $items['ajax-madness/dependant-modal/form/%'] = array(
        'title' => t("dependant modal"),
        'page callback' => 'drupal_get_form',
        'page arguments' => array("ajax_madness_dependant_modal_form",3),       
        'access callback' => true,      
        'type' => MENU_CALLBACK,        
    );  
    return $items;      
}

/**
 * Page with modal form selector
 */
function ajax_madness_dependant_modal_page() {
    ctools_include('ajax');
    ctools_include('modal');
    ctools_modal_add_js();  
    $build = array();
    $build["dependant_select_form"]["#markup"] = render(drupal_get_form("ajax_madnesss_select_modal_form"));    
    return $build;  
}

/**
 * Select the modal form
 */ 
function ajax_madnesss_select_modal_form($form,&$form_state) {
    $form["select"] = array(
        "#type" => "select",
        "#title" => t("Select modal form"),
        "#options" => array(
            1 => t("Modal form @number",array("@number" => 1)),
            2 => t("Modal form @number",array("@number" => 2)),
            3 => t("Modal form @number",array("@number" => 3)),
        ),  
        "#ajax" => array(
            "callback" => "ajax_madnesss_select_modal_form_ajax",
        ),
    );      
    return $form;       
}

/**
 * Select the modal form ajax callback
 */ 
function ajax_madnesss_select_modal_form_ajax($form,&$form_state) {
    ctools_include('ajax');
    ctools_include('modal');                

    $new_form_state = form_state_defaults();
    $new_form_state["ajax"] = true;
    $new_form_state["title"] = drupal_get_title();  
    $new_form_state['build_info']['args'] = array($form_state["values"]["select"]); 

    $output = ctools_modal_form_wrapper("ajax_madness_dependant_modal_form", $new_form_state);  
    if(!empty($new_form_state['ajax_commands'])) {
        $output = $new_form_state['ajax_commands'];
    }           
    print ajax_render($output);
    drupal_exit();
}

/**
 * The form that should be displayed in the modal
 */ 
function ajax_madness_dependant_modal_form($form,&$form_state,$option) {        
    $form["text"] = array(
        "#type" => "textfield",
        "#default_value" => t("Congratulations! You selected modal with option nr. @option",array("@option" => $option)),
    );  

    $form["#submit"][] = "ajax_madness_dependant_modal_form_submit";

    $form["submit"] = array(
        "#type" => "submit",
        "#value" => t("Close the modal & submit"),  
    );  
    return $form;
}

/**
 * Form submit function (never gets called)
 */
function ajax_madness_dependant_modal_form_submit($form,&$form_state) {
    dpm("Got called");
    ctools_include('ajax');
    ctools_include('modal');    
    $form_state['ajax_commands'][] = ctools_modal_command_dismiss();
    $form_state['ajax_commands'][] = ctools_ajax_command_reload();
    drupal_set_message(t("Congratulations! You submitted the MADNESS!"));
}