THANKS for your help!!!
I was using azureus for torrents and amule for classic p2p, that both has support for ip filtering, but a global solution is safer than a client based one, since it prohibits blacklisted IPs to access the system in an OS basis.
I've heard really good words for rtorrent and I'll install it to test it.
I followed the iplist installation proccess (sunrise, emerge etc.), but although it's completed succesfully, both iplist - ipblock don't start.
Following the same steps I installed moblock, but I don't like very much it's command-line interface.
I'll try to install mobloquer as its GUI, but I couldn't figure out so far, how can I install its dependencies.
THANKS and HAPPY NEW YEAR!!!