Recommendations of amp for Martin Logan Summit X

Hi All,
I need a new amp for my Martin Logan Summit X electrostatics. ML doesn’t offer advice on this, so I’m turning to us. I am thinking of the Sanders Magtech, a used Plinius SA 102 or 103, a Jeff Rowland Continuum or Plinius Hautonga integrated. Maybe a David Berning ZH230? Any other tubed amps I should consider? I know there are probably many more; I want to stay under $5000. Any and all help will be appreciated.
Used Pass X series? I use an X350 on a pair of Ascents.

Good hunting.
+1 on Sanders Magtech, but if you want something different sounding, Luxman and Ayre. :)
McIntosh amplifiers also pair well with Martin Logan speakers. A used MC452 would be a good choice. 
I had a pair of the ML Summits and I got great sound from them with a pair of Cary 21AE.