Those are good quality amps. I'd suggest anything
that fits your budget
in the used market from Conrad Johnson, Audio Research, Mark Levinson, or Bryston. The better Parasound preamps should work just fine with those as well.
Preamp recommendations for Aragaon Palladium amps?
I just picked up a first generation pair of Aragon Palladium mono block amps from a local seller and now looking for a preamp. My budget is $1,500; tube or SS is fine but would also prefer a decent phono stage included. Thanks.