Best Martin Logans for under $2000 used?

thanks for taking a minute to help me. I Love the sound of the new Martin Logan Clarities and I was wondering if there are other older martins that sound as good as them or even better. My main concern is for the highs and lows, but mostly the highs. Some Martins can have plasticky sounding highs and I have heard the Aerius and other models tend to roll off the highs and soften them. I am a treble freak and need a fairly bright speaker with crisp highs. I find the clarities pretty good. Also I would like to drive the panels with a tube amp so I can't have huge impedance spikes or power monsters. I have heard some of the vintage martins are tough on amps. Could you also suggest which models you would advise staying away from? thanks again!