Probably the funniest line I have ever heard, if I could rep you (i did earlier today) I would rep you 10 times for that post.
CGI vs PHP is kind of irrelevant. CGI is the technical way that you interract with the web server from your browser, whether it is PHP or ASP or anything. CGI is the only way you can use other languages like C++ or PERL which was widely used before newer scripting languages like PHP and ASP came out. So the real answer is whether you like using PHP,PERL, C++, Java, ASP. If your favorite has to be used with a cgi-bin then you use CGI if not, then you don't need it.
The interpreters for both PHP and PERL scripting languages may be used as (Apache) Web server modules which is faster, or as external (CGI) interpreters which is slower. There is also FastCGI technology which may be used by most scripting languages. PHP is most often used as (Apache) Web server module which would be faster without extra work, and PERL is most often used as external (CGI) interpreter which would be slower without extra work. But the best solution would be to use special proxy software, may be to enable internal Apache proxy feature would be enough for your purposes, but special multithreading proxy software would be much better because it would use less server memory and other system resources.