Most irc people I know use either one of these combinations:
screen + irssi
tmux + weechat
I'm not an expert at all in any of them, but I have used both of them for several years now. And after configuring screen + irssi to get my perfect setup (combination of scripts, utf-8 support and so on and so forth). I decided it was time to make the switch to tmux + weechat.
I'm not going to talk about the advantages and disadvantages of them because everyone has their own preferences and that is fine by me.
One feature that I'm really interested in is the proxy/relay feature of both irssi and weechat. I already wrote about irssi proxy a while ago. So I decided to explore both weechat relay plugins named irc and weechat. I wrote a complete tutorial on how to configure them, but specifically for sdf-eu users. Here is the link:
I hope you find it useful.