This coming from left field:
I'll preface this by saying that personally, I can't imagine spending that much on *just* a headphone setup, but that opinion aside, I'm going to recommend an alternative:
Headphone system budget: $12,000
20 tickets to your nearest symphony orchestra: $200 per concert (center, orchestra level), $4,000
New music pruchases: $4,000 (roughly 250 albums)
My thinking is this: You have A LOT of questions about how certain components will sound. I think it's important to realize once you begin to get into the rarified air of esoteric audiophilia, you'll find that personal taste dictates more in regards to the absolute "rightness" of a system of components than subjective generalizations derrived from short listening sessions at meets.
If you adhere to the mentality that a good system is one that is "okay'd" by consensus, I can assure you that you'll constantly be searching for the next better component. In my personal experience, it's much more fun to search for the next better peice of music. This brings me to a very important (perhaps rhetorical) question:
"Are you looking forward to listening to your system? Or are you looking forward to listening to music?"
Please, please please don't take offense at this line of questioning and the supporting rationale, but it occurs to me that just getting what's "best" component-wise may not be the proper move in truly appreciating the art of music. If that's your intent.
My system is worth roughly $4000 (both speaker set up and headphone), assembled over the course of 10 years. Rarely do I purchase new components; I'm a penny pincher. I recently had the privilege of attending a Boston Symphony Orchestra concert at the Boston Symphony Hall. I am not a huge fan of classical music (I own 3 classical CD's in my collection of ~2000 CD's & ~300 LP's). This was easily the most emotionally involving and amazing musical experience I have ever had. It's difficult for me to find words to express how enjoyable that music was in that place. Honsetly, if I had it all to do over again, I would certainly consider NOT purchasing much of the equipment I own now, and spending the money on listening to more live music. Absolutely, unequivocally, without a doubt, but of course just my honest opinion.