This is a really good question since ml ESL speakers (and stats in general) are hard to find good amps for. They are a challenging load, and difficult to drive. They are revealing to a fault, almost. This can be a great or a terrible thing!
The solid state amps I have that will _work_ with them that I have tried are Aleph 60 Monoblocks (bedroom system), mine were Rawson built and run quite hot, hotter than my VTL Monos do... Love these. A great combo! The speakers are Ascents.
In my (tiny!) office, I have shoehorned a pair of ReQuests. They are powered by a Van Alstine FetValve 500hc. This amp does a decent job powering them, and the gain stage has two 12ax7's in it, which makes it tubey and nice, however the Aleph 60 Monoblocks are better, IMO.
Tubes are a _really_ good idea for these. This is the true sweet spot. vtl MB-450 or MB-300 are awesome. My ARC vm220 monos are great as well.
I know Atma is completely awesome, but I've never tried them...