Von Schweikert VR4JR & Tube Amp???

So...without boring you with too much details, I've been FORCED to move my rig into a small dedicated room in my basement. I currently have the above speakers, Marantz SA8260 SACD/CD, Marantz PM7200 (95wpc), Kimber Silver Streak, Audioquest Montblanc & CV-6. My room is only about 12x10 and it's in a corner of my finished basement so, I have two walls that are poured concrete behind the paneling. Obviously, the sound sucks. Since the room is fully enclosed and mine alone, I literally had to surround the room with R-15 Insulation covered with heavy felt moving-blankets and built some baffling in the corners. Ceiling is typical foam drop-ceiling tiles. Floor is carpeted. After some experimentation with speaker placement, I have ACCEPTABLE sound accross most frequencies except the bass (too boomy). Now here's the question: I'm hoping to make the following hardware changes as final adjustments since I might be here for awhile: Replace the PM7200 with a Primaluna Prologue 2 or Manley Stringray and the Audioquest cables with Kimber 8TC. I don't have the experience with or the ability to audition the considered new gear but, what do you wise and insightful folks think???