Include captions

^st Note:

// Prepare the code for safety
$images = $wpdb->get_col( $wpdb->prepare( "
    SELECT ID FROM %s
    WHERE post_type="attachment"
    AND ID IN ( %s )
    ORDER BY menu_order ASC
", $wpdb->posts, $meta ) );

^nd Note: Look into what you already got:

// Inside the foreach loop
echo '<pre>'; var_dump( $att ); echo '<pre>';

^rd Note: wp_get_attachment_metadata() gives you meta data. Just drop the post ID in there.