var boxes = {
    'main_page': 'about-me-page.php',
    'about_me': 'home-page.php'
};

$('#page_template').on('change update:boxes', function() {
    var selected = this.value;

    $.each(boxes, function(id, template){
        $('#fw-options-box-'+ id)
            .toggleClass('option_hidden', selected != template);
    });
}).trigger('update:boxes');