Speaker upgrade for Primaluna EVO 300 - Looking to find some audio nirvana bliss!

I have a Primaluna EVO 300  with KT120s running into Rega RS5 speakers.  When I use my tube Fosgate phono stage, the system is pretty awesome. ( Warm thick and alive). 

Without the phono stage, the sound is a little thinner, a little less bass, and a little less alive.  I've had my Rega speakers for almost 15 years and am ready to upgrade.  

I listen to rock: REM, Nora Jones, Sound Garden, Pearl Jam, Zeppelin, etc.  

I have an old  Cayin Spark HA-1A EL84 headphone amp I listen to with Grado PS500e headphones.  That's the sound I want.  Thick and real.  It draws me in.  

My budget is up to $5,000.  I'm good with used.  

I'm dealing with limited space or I probably would've already bought the Klipsch Forte IV speakers.  I need something no more than 12" wide.  I'd prefer small towers, like my current Regas.  

What speakers am I looking for?