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!
I've remembered my old ML CLS IIz fondly. They are amazing in what they do right. Fast, transparent and great with Amta-sphere (and other) OTL's. These aren't for everyone, but I really liked them.

Good luck.
I totally agree w/ Rloggie, (except I still have mine ;-) You can't really go wrong with the earlier CLS models either and tube amps (see my system) are definitely the way to go since you're only driving a stat panel. Now that the transient response of some modern subwoofers (such as the self-powered MartinLogan Depth or Descent) can match that of an electrostatic panel, adding seamless bass is easy.

Also, ML still supplies the electrostatic elements for these speakers for ~ $900/pair + shipping. I know of a nice pair of CLS-I's I spied on CL in S.F. that are still available I believe.
I had a pair of CLS MkIIs with modified ladder. I could not get past the very tight sweet spot.

I recommend Maggies- 1.6-3.5. And so do several highly respected reviewers.
cls 2 z hard to beat. Much better to me than new ML models. YMMV