[support] Localizing a template

Hi, I did an Italian language website, I need now to provide it a multi language system, the only issue is that I need to change something in the main page.tpl.php for both languages. I see there're many translation modules but I need something able to change my page.tpl.php from the regular one to the english one (eg: page-it.tpl.php and page-en.tpl.php) as well other than regular text. Something like "localizing a template" Do you have any tips about it? Drupal version is 5.x thanks