I have had several Krell FPB (200, and 700cx) amps which I enjoyed, Aragon makes a good amp, but I think that would be a step back for you, some of the Classe stuff can be had fairly inexpensively since the newer models are out.
I bought a used Classe Omicron and I think it is really something special. The Krell FPB 700cx can be had in your price range, and it will drive anything without flattening out. Of all the amps I've owned, the Krell gets out of the way of the music the best. I found it to be very musical, more so than the older Krell amps. This probably creates an ugly image in your mind, but when I'm really enjoying the music I find myself singing along. With the Krell, I sang a lot!
I bought a used Classe Omicron and I think it is really something special. The Krell FPB 700cx can be had in your price range, and it will drive anything without flattening out. Of all the amps I've owned, the Krell gets out of the way of the music the best. I found it to be very musical, more so than the older Krell amps. This probably creates an ugly image in your mind, but when I'm really enjoying the music I find myself singing along. With the Krell, I sang a lot!