New Highend OC'ed Gaming Rig

My Pentium 4 2.4ghz that I built 6 years ago isn't cutting it anymore and I've decided I need a new one. I've been reading the forums and have decided that a Q6600 is the direction that I want to go and preferably OC it to 3ghz.
I do a decent amount of gaming, and a lot dual monitor multitasking, so the quad core seems to be the right fit. I'm looking for a system that will last me as long as possible (perhaps another 6 years) so I've come to these forums seeking advice.

Although I CAN build the system, I also understand the time investment required for such a task (I ran into problems on my previous system with some bad memory) so snagging a good deal of a prebuild system isn't out of the question as long as the price is reasonable.

Although a bit pricey I've been eyeing a system like this
http://www.newegg.com/Product/Prod [...] 6883229013

Processor-------Intel Core 2 Quad Q6600(2.4GHz)
Memory----------4GB (2x2GB) DDR2 800
Graphics---------Dual NVIDIA GeForce 8800GT 512MB 16X PCI Express
Motherboard---ASUS P5N-E SLI
Case-------------CoolerMaster Cosmos Gaming Tower
Power Supply--600W
Fan---------------CoolerMaster Hyper TX2 Gaming CPU Cooling Fan
Hard Drive------500GB 7200rpm
Optical Drive---20X DVD±R/±RW + CD-R/RW Drive Dual Layer
Another Drive--16X DVD-ROM
OS----------------Vista

Price With Shipping ~$1,800
Buying the parts seperatly ~$1,600

So with a budget under $2,000, is the system above a reasonable buy? Is there a better place to get a similar system? Would you recommend using different parts to build a similar system? Is the above system a good candidate to OC to 3ghz (and possibly ram and graphics card OCing as well)?
I'm not willing to spend $100 for a 1% performance increase but I am looking for a system with some Umph.

I appreciate any comments you may have.

You are correct with the "Unknowns." Although I haven't been able to yet, I would assume calling them up would provide me with all those specifics. (Which I will post here)

As for gaming: "Dual Boxing" WoW and other MMORPG's with 1 computer, and high end eye candy like Oblivion, Crysis, ect. as well as anticipation for future gaming requirements. All of this preferably with maxed out graphic resolutions and clip planes. Would I need SLI for this?

As for appearance, it will sit under my desk, so lights or a pretty case isn't required. Noise isn't too much of an issue as long as it's not very loud, so large fans only. (I'm not ready for water cooled) As long as it's blazing fast at a good price I'm flexible. I'd prefer to keep the price closer to $1,500 then $2,000.

Does anyone know of a place that sells a similar prebuilt system as detailed in the original post for around $800?

Good question Silverion77! Which is why I'm more curious as to acidpython's response. Is there a company buying massive high end hardware at bulk prices and building computers at cheap prices, or is just a case of someone trolling these forums?