Hi, I'm using php-4.4.7 and ez publish 3.9.2 and it runs flawlessly as far as I can judge it. As mysql concerns, I'm happy with 4.1.20.
Regards Michael
I would recommend latest PHP 4.4.7, APC 3.0.14, if you don't use MySQL 5 features, then latest MySQL 4.1.22 is reasonable choice. If possible try compile stack with ICC (MySQL provides ICC compiled packages, no need to compile it).
See Bard's blog posts about it: http://www.papelipe.no/tags/php/benchmark_of_intel_compiled_apache_php_and_apc_on_64bits_server