Some specific questions regarding a new machine

With my current machine getting a bit aged I'm in the process of planning a new one. It is intended primarily for gaming as well as to be the primary home computer in terms of web surfing, record keeping, and occasionally I watch Blu-ray's on it. I already have a 5.1 Logitech speaker system and have been using a 24" Dell monitor, but I'm seriously considering moving up to a 30" running at 2560 x 1600. I will buy that monitor later. No plans for multi-monitor surround. Budget is around $3500, but I could be talked into going higher (Note: I am not planning to build it myself, which adds to the cost. As I have aged I have lost interest in troubleshooting and don't have a lot of time. I'll figure out a design and have a boutique build it).

Here's what I've been thinking:

Case: Big open question. I have a CoolerMaster HAF for my current machine, and I like it. Open to other options.

Mobo: The ASUS Sabertooth X79

Processor: i7 3820 3.6 Ghz

Memory: Corsair or comparable 1600 Mhz 16 Gb

Power Supply: 1050 Corsair, Thermaltake etc

GPU: Dual GTX 670 in SLI

Hard Drives: 250 Gb Intel 520 system drive, 2 Tb 7200 rpm Sata 6Gpb storage drive

Optical: Probably the ASUS bluray player, DVD writer

Sound Card: Creative Labs Recon3D Fatal1ty Champion 5.1

Cooling: ???

System: Win 7 Home

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So here are my questions:

1) I assume for gaming there is little argument to go with a 6 core processor.
2) Should I be saving money with a Z77 chipset?
3) What are the arguments for the 2 versus 4 Gb GTX 670's? Anyone want to argue I should be getting the 680's? Also, the eVGA factory overclocked cards - worth the extra dough?
4) I'm interested in a minimally overclocked and quieter system that still meets my performance requirements. I have water cooling now and as everyone always says - not any quieter. Air or water cooling for this machine, assuming I am aiming for a final processor speed in the low 4's, and do not plan to OC the GPU's?
5) Am I wasting money on a high end audio card despite the good speakers? If not, Aurux versus Creative?
6) Best all around hard drive for gaming? I was originally considering a second SSD as a dedicated Steam and gaming drive, but that would chew up the only other SATA 6 connection the mobo has, and would probably have no effect beyond loading times. Thoughts?
7) I'm planning 16 gig system ram, so was thinking Windows 7 Home. Why pay for Pro when Windows 8 is right around the corner? Are the OEM Windows 7's shipping with upgrade coupons? They did that with Vista --> 7 I remember.
8) How long do you think the "power on to applications ready to go" time will be for this? I'm thinking about making the switch from "computer always on" to "turn it off when I am done."

Thanks!

John
9) Anything else I haven't thought of here?