What would be a good amp to drive a pair of Martin Logan Impression ESL 11A?

They usually are around 4ohm or lower from ~80Hz to 200Hz, so that’s a bit taxing.  
  
John Atkinson usually estimated their sensitivity as -3dB from advertised, so instead of 91dB, your’s is likely 88dB.  
  
Your Linn does not state at what ohm that 90W is happening at, I’m gonna bet it’s at 4ohm, which makes it a ~50W 8ohm amp. 
 
I would say to look for at least 150W into 4ohm, preferably at least 200W.  
  
 The Anthem is 400W into 4ohm, so no issue there. 
 
The ATI AT522NC also looks good.

pvmike

Seeing the amp doesn't have to do bass, I would go for the higher sweeter sounding Class-A biased Parasound Halo A21 as it will drive the low impedance of the ML's esl section no problems and have the current to back it up.

Continuous Power Output

 250 watts RMS x 2, 20 Hz - 20 kHz, 8 Ω, all channels driven

 400 watts RMS x 2, 20 Hz - 20 kHz, 4 Ω, all channels driven

 Current Capacity 60 Amperes peak per channel

Cheers George

  

I used a BAT VK500....plenty of juice and I agree with the previous posters.

Since I own a set of the 11A's, I am motivated to break my oath of silence (at least as far as forums) and add my own "sage wisdom" to the mix here and strongly encourage you to audition any amp candidates with your own components if at all possible. I have three main reasons:
First, the 11A's have only a single set of binding posts so the speakers are receiving the full range signal and will respond to the characteristics of the external amp even in the bass range, despite the fact that the onboard woofer amps should be providing the grunt from 300Hz on down.  The 11A's are capable of extended and very articulate bass and you will likely hear significant  differences depending on the amp they are connected to.

Secondly, while adding more power and current capability is a logical step and the Logan's should respond positively to more juice, you may run into the old issue of  preamp/ amp matching going forward. I could not find the output impedance of your Linn listed online but the Decware preamp appears to have a high(ish) 600 ohm output impedance and may not mate well with the Anthem MCA225, as it has an input impedance of only 10K ohms.  Of the two amps you list, the Parasound looks a bit better on paper.

Finally, while any good speaker should allow you to easily hear changes in your components, the stats are very revealing and only you can decide if you like what you're hearing with a given combination. Looking at specs or getting advice may point you in a given direction, but your ears should be the final arbiter. The hunt can be either frustrating or fun, depending on your mindset,  but the rewards will be worth some effort.

I suggest a Sanders Magtech or Innersounds Electrostatic amplifier. 
And I suggest (as I have done many times) Roger Sanders excellent white paper on tubes vs. Solid state as useful reading as you begin this journey.

Thanks to everyone that has responded to this thread so far further feedback is always welcomed. I want to say that I did talk with Roger Sanders for about a hour and liked everything he had to say. I would love to try a Innersound ESL amp but my pocket book is thin. SSDI dictates what I can afford and about $2000 is my limit.