Suggestions for my system

Agree with @jafant . Start by auditioning power cords. IME, they can offer a dramatic change in depth and width of soundstage.
  I'm using Audience and Furutech which present a spacious and deep image.

@jafant and @lowrider57 I’ve experimented with power cables and have settled with a shunyata system. I have a dedicated line feeding a shunyata Denali with Alpha NR’s feeding my integrated and source. I settled on these after I noticed gains in both blacker backgrounds as well as soundstage depth. Really happy with what that upgrade brought to my system. 

Nice. Seems like you've done well with your power setup.

I listen to classical almost exclusively and have chosen components (within a budget) that present the qualities you're looking for. It's all tubes, but I believe you can still achieve your goal with SS.

Your Harbeths are known to be fast and articulate. Can these speakers achieve 3D holographic imaging? And perhaps the small room is limiting their performance.

@lowrider57 What tube components are you using in your system and have you compared it to ss gear with classical?

@mikecorwin , yes I have compared classical and chamber music with tube and SS. 
First, the reason I say wide soundstaging and holographic imaging can be achieved with SS is because I owned a Sunfire 300 amp which presented a soundstage that  went deep into my front wall. It all depends on the design. I think McCormick amps are also known for this type of presentation. I dont think the British designers put as much importance on this aspect of sound reproduction.
And btw, I've always used tube preamps with SS.

Currently, I own an EAR 534 push-pull Class A amp. The preamp is Audio Note. Tubes will give you realism, IMO. Realistic tonal qualities of acoustic instruments, realistic attack and decay, more sense of being there. Of course, it's design and system dependent. I also have another tube amp which does very well except for the holography.
My tube components allow the orchestra to sound naturally layered. Many components can provide a black background which allows you to hear separation of instruments. But, the right tube setup sounds organic and spacious. 

My system has deep tight punch to it, but it would not fall into the category of PRAT. Each component was chosen to have synergy for classical music. It also does very well with jazz, especially older jazz combo recordings.

Hope this was informative.