At the risk of sounding like a broken record, the best transmission line speakers I have heard are the JM Reynauds. I am a big fan of the (now doscontinued) Offrande speakers, but the entire line shares many of the same qualities: warm, liquid, detailed and a remarkably wide and deep soundstage.
http://www.jm-reynaud.com/jmr_us/jm-reynaud_fr.html
Good luck
http://www.jm-reynaud.com/jmr_us/jm-reynaud_fr.html
Good luck