Ubuntu Networking :: Parental Control/web Content Filtering?

I work at a cybercafe and i am currently plagued by users who, despite the warning not to, continue to watch porn and use p2p software on my connection. I have done some preliminary research on how to filter the web content as well as to reduce the bandwidth used by p2p software on my network. I found that a solution that has worked for many with regard to web content control is danguardian + squid or privoxy in conjunction with a firewall like firehol or something of the sort. Others use an os like untangle or clear os and install it on a stand alone server. then others use open dns. although i would like the open dns solution, i will need to install a dns client, ddclient and i am a linux newbie so and ddclient requires some compiling or so, and i'm not yet into that. I am also currently not in the mood to dabble into untangle or clear os bcos it will cost me a lot do download the iso's. Internet access is costly over here.

Before i go ahead to implement the steps in any of the tutorials i have seen, i am wondering if such a measure will even help at all.You see, at my cafe, i use my server to share the connection to all my clients. I connect to the internet using a gsm modem. then i have two nic's. nic1 is set to share my connection and my router connects to that nic1. nic2 connects to my router using a static ip to enable communicate with my clients. If i implement something like dansguardian on my server, will it solve the problem for me, that is, do i have to also re-implement the steps i took to configure dansguardian on all the other pc's, that is, my clients?