Until now we haven't seen any serious clans on http://www.l2final.eu but still you can go and search for a clan on forums http://forum.l2final.eu/ .
To be honest I was expecting to see some high ranked clans here since there isn't any other serious EU L2 project left (GF client).
Anyway there's still time left to find your self a clan , so enter our forum and search for one , also try to inform other players for its grand opening .