Vacuum Tube Preamp for Solid State Power Amp Pairing

Check out a VTL TL-2.5.  I have owned one for many years and sounds good with a solid state amp.

:You have a good budget.  A used Conrad Johnson preamp with a remote for volume would be another good choice.      CJ Premier 14 or later have remote volume

     Tube gear tends to vary more in sound than do solid state gear.  Different design, tube types employed, etc. have a bigger impact than differences in parts and design of good solid state gear—an Audio Note linestage will sound very different from an Audio Research linestage, for example. If you can, you should audition each candidate, and preferably in your system.  
     Trying different brands of tubes (tube rolling) is not something you must do, but, if after becoming familiar with your linestage, you wish to explore changes in the sound, tube rolling is an opportunity not afforded owners of solid state gear (no transistor rolling).

     You should be able to find tube gear with all of the features you like.  If balance control is not on your list, you might consider including it.  Tube gear can develop imbalances (a tube getting weak, tube socket getting dirty, etc.) that, if minor, can be dealt with by a balance control until it gets severe or you decide to chase down the cause.

Linear Tube Audio Micro Zotl mk2 

a great preamp and easy on tubes  check it out.

Audio Research SP-3-1A. Classic!