I was about to say Fostex myself, as I own both TR20p and TR50p.
Before you dismiss it keep in mind the price gap. I got my 50s on sale at b&h for $74.99 with free shipping - quite a few cents cheaper than $1000 headphones you are looking at...
I think they sound wonderful and so far only headphone which was a bit better sound and fit there these
Sony MDR-SA5000
Measurements are valid, but they are not everything. Get Foster (if store allows returns) and hear for yourself.
p.s: there are many forums posts dedicated to modifying TR50p to achieve much better sound
Fostex T50RP modification summary links