$1000 to spend on an amp used

Hafler 9290, 9300 or 9500

A Coda 11 will be bit more than 1k, but a Bedini 100/110 mkII should produce a pretty satisfying result w/ the gear you have.

I agree with Semi. Go with a used Forte Model 4. It's built like a tank and is definitely one of the sweetest-sounding, highly detailed amps you'll ever hear. The detail is "real detail", not brightness masquerading as detail. But don't let it's sweetness fool you, it's dynamics are uncompromising. Yes, there are amps, which outperform it..... for several thousand bucks.

p.s. As with any used gear, just make sure it's guaranteed.

Quad 909. Seems the obvious choice given the speakers and preamp.

Thanks for all of the responses. I ended up going with the 909. I am very happy with the sound. Next up is a new CDP.