Most of us build systems over decades. Typically this is how folks that really love high quality reproduced music with budget constraints do it. Each step should be carefully planned with the result of having a synergistic system with each component of roughly equal performance at some point. Then you enjoy for years until you can upgrade to the next level.
I think your question is great. I was there once. It would be great if you posted photos of your system and venue (under your UserID), this can really help in assessing and recommending equipment and placement.
Lots of good advise (minus the spend on power cords and interconnects). If this is part of a journey to create a great system an say you have $10K now and can come up with another $2.5K every year… then you can work towards a really great system in three or four years… with very substantial improvements every year as you get there. The time frame is important, in that, there is lots to learn. Read, listen, read, listen, repeat. If this appeals to you… we can really help. Your goal will change as a result of listening and making changes.
Typically I will always start with speakers to define “the next level”. Speakers typically are the most important component. They really define the sound. They must be sized for the space… and the technology capable of making you really happy. So for instance… if you were into rock… B&W speakers… heavy on the bass… then you choose electronics to complement them… massive MacIntosh amps. The first 30 years of my pursuit of the high end was dominated by planar speakers: electrostatic (like Martin Logan), ribbon (Apogee), and Heil (Air Motion transducers), but the last twenty has been traditional dynamic cone speakers.
You like a really good midrange and a good bit of detail…so a natural / musical speaker… Totem, Sonus Faber could fit the bill. See my systems… I think, these would make you happy… but are too expensive right now.
To get to where you want to go… unfortunately you will want to replace everything. Combined units are not good and you have budget speakers. This means there are a lot of appropriate paths. Certainly making it confusing. There are a lot of good choices.
One might be $5K speakers, $2.5 Preamp (definitely would not hurt to go for $3.5K used here), and a $2.5K amp. The preamp should be tubed… I would recommend a used Audio Reseach LS for the preamp.
Education: Read Robert Harley’s The Complete Guild to High End Audio, get a subscription to The Absolute Sound and Stereophile. Go to any local high end audio stores… listen. Tell them you are at the beginning of a search… you need to get a feel for the sound you are looking for. If you can find a high end audio dealer that can coach you… that really helps. I have had three fantastic relationships with owners of audio stores. My audio guy in Portland, a friend for 20 years, has dropped by a pair of Audio Research Reference 160 monoblocks… which I have been using for 8 months ($32K).
Once you get the basic components… then you can work on interconnects and cables.