I want something with acoustics which resembles the sound in the Concertgebouw in the best seats. (I know it also depends on the musicians, size and placement of the orchestra, but the overall sound is warm and extremely detailed)
what you want isn't available in commercial music recordings, home playback - have you listened to your reference recordings on high end (or rather actually "good") $$$$ speaker systems, speakers properly placed in a big enough and well sound treated listening room?
that's usually the "best" presentation since that's the way recordings are mastered, expected to be played back - and it still isn't exactly "like being there" - and theres lots of controversy over what are "good" speakers, frequency/phase response to directivity, to exact room treatment goals
in fact most recording tech is about painting a "hyper-real" illusion from the very start of the process with multiple microphones with mic type selection, placement and on through lots of signal processing of those many mic feeds treated with EQ, compression, added reverb... all aimed at exploiting human perceptual illusions, tricks, even cultural conventions in the mixing
headphones are always going to sound different than speakers in a room - headphone "sound stage" is joke at best without binaural recordings or virtualization processing
and why buy different headphones to just make frequency response changes that EQ can handle - the HD800 do seem to be basically OK in broad, smooth range of response, relatively low distortion
you can however get very close to what the mastering engineer heard by using the Smyth Realizer, getting personal calibrations in the mixing studio hot seat - or "collect" dealer's demo rooms, great private setups - anywhere you can rent, cajole, bribe your way into the sweet spot for 1/2 hr with the Realizer for a personalized measurement