Upgrading preamp and phono

I'd like to add a recommendation to you even though finding a used one may be hard, but new is not out of your price range either. I've been extremely happy with the build quality and performance of my Finale Audio-Triode labs integrated and highly recommend their products for value and all out build quality sound quality.

They have a few preamps that will fit your bill and price range with excellent phono stages built in or separate.

I can't say enough about the sound and build quality of my F 3008 300b integrated amp. they are also a very nice bunch to deal with and very helpful. also all made in North America, Toronto Canada to be exact. They use some of the best parts available period.  These are sister companies FYI, Triode labs focusses more on the very low power stuff ( think 2wpc) Finale a little more powerful amps. Some of the best tube amps preamps I've come across and I've owned Cary, CJ, Audio Research VTL and more.

http://www.finaleaudio.com/

http://www.triodelab.com/