Admin File Download

I’m interested in providing a secure file download in the admin section.

I’ve got it working by adding actions as such:

if(is_admin())
{
	add_action('admin_menu', 'my_plugin_menu');
	if($_GET['page'] == 'my-plugin-download')
		add_action('admin_init', 'file_download_func');
}

I’m wondering if there is a better way to find out that the page is loaded, yet still send the content before http headers are sent. Any ideas?