I am looking for recommendations in the $1K range
In my opinion, in that range the Audio-Technica ART9 is an absolute no-brainer.
In my system it plays as well as my VdH Colibri XGP, Benz Ebony TR and Allnic Puritas and when I've brought it along with me for testing in other systems, it's done equally well against offerings from Lyra, Zyx and others.
The Herron offers 64dB or 69dB gain, so I see no need to restrict yourself to .5mV or more. If you've got it set up for 64dB you should be fine down to 0.3mV or even less, while 69dB should be be fine down to 0.2mV or even 0.1mV depending on how quiet the Cronus Magnum 2 is.