Hello Yada,
I'm a dealer for several of the amps mentioned here (Parasound JC-1's, InnerSound, Wolcott) as well as a few not mentioned here (Clayton, Atma-Sphere) that also work very well with electrostats. My experience is mostly with Sound Labs since that's what I sell, though I do have a few customers with CLS's who have bought (and are happy with) either Wolcott or InnerSound amps. Some very good amps that I'm not a dealer for include Accuphase, Jeff Rowland, and Pass Labs. Someone mentioned the Halcros, but one of my customers tried Halcros on his Sound Labs and found that it wasn't a good match.
Each of these amps brings a slightly to significantly different set of qualities to the table, and I'd want to dig a bit more into your personal priorities before making a specific recommendation. For example, do you think you'd be more interested in a neutral-voiced solid state amp, or one that's voiced a bit on the warm side?
By the way, Yada, I think the CLS is the most physically beautiful loudspeaker ever made. And among the very finest sonically as well. In my experience the amplifier/speaker matchup is considerably more critical with electrostats than with dynamic speakers. But there are plenty of excellent amplifier choices well within your budget - the thing to do is to match up the right amplifier for your personal priorities.
Best wishes,
Duke