Any stereo will improve detail simply because HT squashes detail. I would look at new speakers, not so much because ML are bad as they are so inefficient your hands are tied and amplifier choices severely restricted. Those 89dB Kharma will not be much better. Ulfberht's with upgraded crossovers will be more work but walk all over them in the end. While costing a whole lot less.
If you want to stick with ML, probably the bulk of your low resolution is coming from the HT processor. All of my gear the last 16 years has been purchased without audition but rather based on extensive on-line research. On that basis looking at what you have I would be looking very seriously at the Townshend Allegri preamp and having Steve McCormack build me some amps, to be connected with Townshend F1 interconnects and speaker cable. The whole thing including seriously upgraded Ulf's will run you way less than your budget, including putting everything on Pods and Podiums. But the detail and imaging you are looking for, forget about it. Whatever you heard, and then some.
If you want to stick with ML, probably the bulk of your low resolution is coming from the HT processor. All of my gear the last 16 years has been purchased without audition but rather based on extensive on-line research. On that basis looking at what you have I would be looking very seriously at the Townshend Allegri preamp and having Steve McCormack build me some amps, to be connected with Townshend F1 interconnects and speaker cable. The whole thing including seriously upgraded Ulf's will run you way less than your budget, including putting everything on Pods and Podiums. But the detail and imaging you are looking for, forget about it. Whatever you heard, and then some.