Recommend Class a Amp

I would see is I could find a used Bryson or Pass Lab amp that meets the output you are looking for.

Those are not the easiest speakers to drive. Class A isn't out of the question, but it may not be realistic given your budget. If you could find a pair of Pass Aleph 0's or 1.2's, you should have no problems driving those speakers as long as you aren't in a really big room and demand loud volumes. Another option, if you like Krell is to find a good used KAV-250A. I used to have one and its very under rated because its part of the KAV line and not the KSA. I've seen several of them go in the last couple of years for well under 2k. Other than that, a Bryston 4 comes to mind, along with a McCormack DNA-250.

KSA aren't class A amps on the first place. 250wpc class A amp would be required to run in separate room preferably Freon cooled. it has pretty good range for class A power and that's why it can also work as local heater for room up to 220sqf.
So maybe you'd reconsider your objective..
I was hooked up on class T amps more than decade ago and never looked back. The way they sound to me is most natural and clean with no limitation to reproduce truly uncompressed recording material at any volume levels seriously. It's also cost effective as well. Try for very cheap BelCanto S300 and you would be surprised it won't be worse than with KSA 250.

"03-26-15: Czarivey
KSA aren't class A amps on the first place."

Actually, it may be. As long as the load doesn't drop below 3ohms (its either 3 or 4 ohms. I'm pretty sure its 3), the amp will be running in class a. So with the right speaker, it can be a class a amp.