If you decide on planars, you have some great choices. As others have said, you should if possible hear the Sound Lab ESL's. Also the Sanders ESL's, and a new entry--- the ESL with direct drive (no transformer in the speaker) tube amp by Music Reference. MR owner/designer Roger Modjeski designed a similar system for the legendary Beveridge ESL in the 1980's. Factor in a round-trip flight to Berkeley, CA to hear them!
If you have the room for the ESLs above, you have to hear (if you haven't already) the big Magneplanars. Many consider the 3.7i the highest value speaker available, and the bigger 20.7 a great one as well. Be forewarned---they require as much amp power (current---tube amps need not apply) as you can afford. A minimum of 200 beefy watts per for a small room, more for a bigger one. If you have a REAL big room, use a pair of Tympani IV's as (sub)woofers for them!