I have a new question concerning this problem. Currently we offer PHP4 (4.4.9), PHP5 (5.2.8) and PHP6 (dev).
I would like to add one more PHP version, PHP5.3, and offer it separately. Is there a way to do this cleanly? The 'phtml' was kind of hack-ish.
If you rely on the "AddType application/x-httpd-XXX .php" to determine if SuEXEC is available, might I suggest checking for "AddType application/x-httpd-php(.*) .php"? That way I could do something like "AddType application/x-httpd-php53 .php", which would be a lot cleaner.