You have some great options in that $500-$750 range, and I'm familiar with all the bands you listed there, so I can totally help! Here are some systems you should look into, along with prices and pros/cons:
SETUP 1:
Stax SR-Lambda (standard bias, original version)
+ SRD-7 speaker tap adapter (it will be $325 or so for headphone and adapter together)
+ Topping TP22 Tripath Speaker amp ($95)
+ AudioQuest DragonFly Red ($199)
+ AudioQuest Golden Gate 3.5mm to RCA cable ($65)
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Total cost: $685 + shipping
PROS: lightning quick attack and decay keeps your head nodding to the music. Unbelievably fast sounding. Punchier and more impactful than 98% of electrostatic setups due to thicker diaphragm and extra dynamics from speaker tap adapter. Super resolving (which is why I recommend the upgraded interconnect) - clarity and resolution is unrivaled for the price... right at the doorstep of the HD800. Super lightweight with very little clamping pressure - you barely feel them. Excellent sparkle and mids make the guitars sound super exciting and energetic. Microdynamic texture is among the best of the best at any price.
CONS - Not much in the way of deep bass extension. Midbass punch on kickdrum is fantastic, but low, rumbly bass is mostly absent. The headphones will also be fairly old, so they may not look the best and the headband can feel a little brittle (though it can be replaced).
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SETUP 2:
MrSpeakers ÆON ($699 preorder)
Amp ???? Worry about the amp later. A $199 DragonFly Red should do it justice or grab a Chord Mojo down the road and be set for headphones for the next two decades.
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Total cost: $699 plus a later investment in the system.
PROS: You'll have the headphone problem solved. ÆON will be fine out of a phone or stopgap solution (like a used Fiio E17 or E12) to keep you relatively on budget out the gate. You can reinvest in the system later and continue to reap benefits as it scales. This headphone is unquestionably the best total package ever at this price: fantastic neutral tuning, easily EQable, excellent punch/attack/decay, easy to amp, extremely comfortable. It is dangerously close to the $1,899 Ether flow for barely more than 1/3 of the price. Safest, most future-proof pick.
CONS: stretches your budget a bit to build up the system, but IMO it is absolutely worth it.
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System 3:
Emu Teak ($500ish)
AudioQuest DragonFly Red ($200)
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Total cost: $700
PROS: Dat bass!!! This is probably the best of the Fostex TH900 variants, offering better overall tone and decay than the popular TH-X00 (which can get a little sloppy with your music). I believe
@shuto77 is using this setup currently, so he can probably give you more insight into it. My experience with it is somewhat limited.
CONS: Not as resolving as the two systems listed above, but it's no pushover either.
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System 4
Audeze iSine20 $549
PROS: perfect tuning, speed, impact, dynamics. Great resolution and soundstage for an in-ear. Cypher cable actually has a decent sounding amp and DAC built into it.
CONS: it's an in-ear. Love it or hate it fit. It's also an in-ear that doesn't really isolate. Hard to argue with the sound though.
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There are a few options that are old favorites of this thread like the HE400i and HE560, but you wouldn't have much budget left to amp an HE560 satisfactorily and it would be hard to recommend the HE400i as an alternative with any of the above options on the table.
IMO, the MrSpeakers ÆON is probably the safest investment of the options on the table above, looking at the big picture of long term satisfaction, versatility, scalability, durability, etc. It's a headphone that really curbs the upgradeitis, because it does so many things and it does them so well. Just my two cents.
Cheers!
Fortunately things have improved a bit though, so here we are! 
I was just thinking of the Chicago meet we were both at earlier this year ....... bang'n to Rage Against the Machine .....that was a frigg'n cold day wasn't it?
