Originally Posted by KlenTelaris

Ok considering you are new in this,i would recommend to use nginx proxy to apache,that is configuration where nginx handle static files like images/videos and php is handled by apache,so then you dont need to bother with special php configuration,and also everything works fine then as php is handled by apache(apache htaccess can be used then as well).
I peaked at google to see what they say about varnish and found this article:
http://rtcamp.com/tutorials/why-we-n...sh-with-nginx/
and i agree with article author as nginx indeed can be optimized enough so then there is no need for any further optimization.

As you would use nginx proxy to apache,you will then have chance to optimize both nginx and apache,and then might not be need to use anything else further.

So in shortly do this and post back when you get results.