I use the example code of the piklist-demo to reference woocommerce products within my custom post type. For simple products this works right out of the box. But I can´t get my head around how to do this with product variations:

 array(
        'type' => 'select'
        ,'field' => '_' . piklist::$prefix . 'item_contracted'
        ,'label' => __('Contracted Item', 'myinventory')
        ,'columns' => 12
        ,'choices' => piklist(
          get_posts(array(
            'post_type' => 'product'
            ,'numberposts' => -1
            ,'orderby' => 'title'
            ,'order' => 'ASC'
          ))
          ,array('ID', 'post_title')
        )
        ,'relate' => array(
          'scope' => 'post'
        )
      ) 

Would be great if someone could point me in the right direction.

Thanks Sebastian