[CentOS] How to setup a computer using CentOS6 as a firewall for the whole network in my place?

> For a newbie one like me ... which option you would advise me to go for?
> I do not have any special preferences but I do care  for the one that 
> is more stable and provide really more security.

It seems to me that the last line of my previous post already contained 
my answer to your question :-)

"I use Linux servers and a pfsense firewall to protect the network. 
Works like a charm, with amazing stability and reliability."